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RobS
September 28th, 2012, 05:15 AM
Hi there. This is my first posting - could be my last.

The Honeywell 200 seems to be extinct; correct me if I'm wrong. I intend to try to provide a remedy, a replica built from original Honeywell parts from around 1969, more a pastiche though really as they're too modern. I have almost enough components, but if you have any that might be suitable in your museum or even just remember what a Honeywell 200 looked like please respond.

By the way, don't believe that the H-200 killed the IBM 1401 like they say in the histories. I think the 1401 died of natural causes.

Rob S

Chuck(G)
September 28th, 2012, 08:23 AM
I always liked the H200's futuristic (for the time) styling. You've got quite a job ahead of you.

The 1401 (and 1410 and 1441 and the 7010) were in use well into the 1970s and many lower S/360 and S/370 systems were run in 1401 emulation mode after IBM withdrew support for the older systems. I don't think that IBM ever considered the H200 as any particular threat. Once IBM got its foot in the door of a customer, it was very difficult to dislodge.

RobS
September 28th, 2012, 09:19 AM
I agree with you. I have read a document written by Dr. William Gordon, head of the H-200 development team, setting out the original proposal for the design of the H-200 and in it emulating the 1401 is treated as almost an afterthought. It's just the pat historical records that call the H-200 the 1401-Killer. I understand that it did cause the IBM management to set a very rigid date for the launch of the 360 as damage-limitation though. Our company went the same internal emulation path with successive generations of Honeywell machine. I had old programmes from the H-200 days still running under not one but two levels of emulation when we were using a Honeywell model 66. If you're wise you stay with what you know best.

The visual style of the H-200 is just one reason why there should still be one somewhere. I knew someone who had the control panel from one as a souvenir but he threw it away when he moved house. I intend to build as precise a replica of that panel as I can but I only have less than thirty of those original iconic illuminated push-buttons and the panel needs over fifty, so I'll have to improvise a bit. After doing that designing the logic should be a walk in the park.

Rob S

Chuck(G)
September 28th, 2012, 10:09 AM
Are those button caps simply acrylic? If so, it should certainly be possible to machine or cast them and fit them to contemporary illuminated pushbutton bodies.

I never got to see a 200 up close; my first contact with Honeywell iron was via a friend who'd taken a job in Phoenix (at the old GE computer plant) in the early 70s with them. I got to take a stroll through the ill-fated water-cooled 66/85 prototype they were working on--really, just a bunch of free-standing racks sitting inside of an enclosure that you could walk into. The console the engineers were using was very impressive--Nixie-tube bar-graph displays in particular caught my eye.

RobS
September 29th, 2012, 01:48 AM
Yes, inch long chunks of three quarter inch square translucent plastic, don't know which kind but acrylic seems likely. The problem I see is getting or casting acrylic with the same colour and density of translucence as the originals. I assume one adds some ingredient to the clear mix to cause the effect. Perhaps a professional encapsulating firm would know how to do it. Not all the buttons need to light up, but the whole style of the panel would be ruined if they didn't all look the same and I don't want to abandon the originals entirely and use all replicas. Provided that I grouped old and new buttons separately it might look acceptable.

Good news regarding memory for the machine. Someone in Amsterdam has offered me several 4k H-200 memory banks with supporting driver boards. That will solve one problem.

I'm being very pragmatic about this project. At its conception I christened the planned computer "Honey Pi" after the Honeywell 200. I changed Honeywell to Honey because it won't be entirely Honeywell and the 200 to Pi because the project may be irrational and never end. Its signature demonstration programme is to compute Pi beyond the Feynman point (767 decimal places) using only 2k bytes of memory and no hardware multiply or divide, printing the result progressively while doing the calculations. I have already written and tested the programme on a PC-based emulator and the H-200 would take 14 minutes 1.9 seconds to run it to 770 places, so all I need now is to build the real computer, which will take me much longer.

When I've made some significant progress to report I'll open the honeypi.org.uk website to document it so that I don't fill this forum with details, but building that will just add to my work.

Chuck(G)
September 29th, 2012, 09:05 AM
I'd definitely talk to a plastics firm. You can tint casting resin, but it's a tricky business. Don't overlook the many model-making fora that are online--there's a wealth of information there.

What are you going to do about peripherals for your system?

RobS
September 29th, 2012, 10:02 AM
My view is that the equipment should be visually interesting, hence the reason why the Pi Factory, sorry didn't mention before that's what I call my progressive Pi algorithm, starts printing immediately and not fourteen minutes after everyone has got bored and left. I originally worked on a punched card H-200, but that's impractical in our spare bedroom, so I'll try interfacing to a Dataplex machine that I have. That has two magnetic card reader/writers, you know the cards the same size as a punched card? They hold 12.5k bytes apiece, equivalent to around 150 punched cards, and when they slide back and forth through the reader with the read head going sideways to change tracks they look pretty stupid. I suppose it didn't take long for someone to make the magnetic media round, spin it around instead and call it a floppy disk. The Dataplex sits easily on a desktop, so it won't cause any domestic issues. It was designed by Englishmen. Here's the American patent application http://www.freepatentsonline.com/3860793.pdf but don't blame them for the magnetic card idea because I think that was an American invention first. Our company used the Dataplex for word processing for quite a few years. As an alternative to the Dataplex I could get really modern and use eight inch floppies, single-sided hard-sectored ones of course. I have a few packs of those and a drive.

I haven't decided about hard copy output yet. Printing devices suffer too much wear to last. I have all the H-200 electronics to interface to an IBM Selectric golfball typewriter but I doubt that I'll find one. It's more likely that output will be to a screen of some sort until something come along. If I get as far as worrying about hard copy output no doubt somebody out there will realise that I'm being seriously successful and offer something. I've got a Wang daisy-wheel printer but who in the world understands their weird dual coaxial communication protocol now? If I want to use that I'll have to hack straight into the interface microprocessor board and bypass their connection method altogether.

The other possible medium is paper tape, although it's no fun to handle. I have a box of sixteen reels to hand just in case. Again the machinery would be entertaining as I have a punch and readers from a Flexowriter and interfacing the H-200 to relays would be a good puzzle. One of the readers is a Selectadata device with the two speed gearbox for fast searches. I stripped down and rebuilt the punch not so long ago because the parity checking contacts were filthy. Of course the Flexowriter itself is long gone, worn out printing machinery you see.

That's me off the grid for the evening now. We've got a big time difference between us here you know.

Chuck(G)
September 29th, 2012, 10:06 AM
Sign up to the cctalk mailing list--there's a lot of older gear (including TTYs and Flexowriters) lurking among the members there--and much of it on your side of the pond. The list's web page is here (http://www.classiccmp.org/cctalk.html). Be patient--the list is sporatically administered.

Note my avator--an NCR CRAM magnetic-card storage device. I learned to despise that beast.

MikeS
September 29th, 2012, 11:54 AM
Sounds like a worthy project for sure! I've got a couple of those mag card drives (and one card ;-)) in case you need any parts...

RobS
September 30th, 2012, 09:15 AM
I took a look at cctalk but at the moment I think I should be doing some of this work that I'm promising as there's plenty here without getting more. I'll bear it in mind though so thanks for that.

I remember hearing about those CRAM devices at my company but it was told to me more as a joke than a sign of progress. I suppose like a lot of things, including the H-200, it was great when it worked. I feel for you.

RobS
September 30th, 2012, 09:42 AM
I don't even know whether the Dataplex works now. I haven't taken it off the shelf for years and I'll probably put my back out when I do. One card? When I acquired equipment I'd always take everything else connected with it from the engineer's room, operator's room, encoding room (not the girls though, well only once and I put her back later), but at least manuals, media and spare parts. That's why I have over 300 spare light bulbs for a H-200 which doesn't exist yet. At least if I build it it'll be a while before I have to convert it to LEDs. That said, I did have to buy some spare bulbs for the Dataplex as it has several photocell motion detectors in each card drive which sort of rely on them to work.

Thanks for mentioning that the project is worthy. I need encouragement. I put it off for two and a half years to write a novel instead but at the moment I think this project has more support than the novel. That's strange because it's about people living in the 1960s who are able to communicate with people living in the twenty-first century. It's science fiction of course. :)

ClausB
October 2nd, 2012, 01:33 PM
Cool! I wish you luck.

An H200 was the first computer I ever programmed, though I only saw it once. Back in 1975 my high school offered a FORTRAN class. We rented a keypunch and sent our card decks across town every night with the school's janitor who lived near the computer facility. The next day we got our printouts back (I still have some of them). The long turn-around taught me early to debug in my head. One day we took a field trip and saw the real thing.

The next year the school bought two Altairs with MS cassette BASIC.

RobS
October 3rd, 2012, 05:58 AM
Even in our business environment our development work was run overnight, so we also got only one shot a day at running a programme. I agree that it is good training. Personally I somehow never acquired the habit of making mistakes in the first place because I did what I was taught and nobody taught me to make them. The first programme that I ever wrote on a training course was immediately flawless and I carried on that way for years. Our managers were scared by the way that I worked, using all the available scheduled time to design my programmes with virtually no time left to correct errors as I didn't plan to make any, but they got used to it. Nowadays trial and error development is so fast that even I resort to it, but mainly because modern computer systems don't necessarily do what they're supposed to in reality or they are inadequately documented. I have to be extremely careful building my H200 as the parts that I have are irreplaceable and burning any out could end the project.

I went on a FORTRAN training course in 1972 because our company normally used COBOL but valuation of our liabilities involved complicated actuarial calculations which would have been inefficient in COBOL and our actuaries used FORTRAN for their research tasks. I discovered that FORTRAN couldn't read or write the large COBOL tape files that we used then, so instead I wrote a COBOL programme to handle the files with an EASYCODER module embedded in it to do the calculations. EASYCODER was the assembly language of the H200 but the brilliant design of the H200 hardware meant that it was halfway between more modern low level assembler languages and something like BASIC, so not too great a strain on the brain. This wasn't anything brand new but just another step in the work already done by IBM, Honeywell and others. By building the replica H200 I can demonstrate the versatility of the H200 machine language better than by simply writing an emulator, which I also need to do anyway.

Computer architecture is a balancing act between cost, performance and complexity. Magnetic core memory was extremely expensive when it was made by hand, so early computer logic did as much as possible in one instruction to keep programmes small. Semiconductor RAM became very cheap and processors became much faster, so instructions could do less and RISC processors became viable. Then processors became so complex that they could do highly specialised tasks again, like the video processors in modern gaming computers. The H200 is an example of where this balancing act started. I have several Honeywell Level 6 and DPS6 minicomputers which I am about to donate to a computer museum. They are an interesting transitional phase in computer architecture, having RISC style bit-slice processors executing microcode on ROM to implement the more complex machine language that the programmes actually use. If you changed the internal plug-in ROMs in a DPS6 it could behave like some other sixteen bit computer, which would be fun. Perhaps one could even be converted into a PC. I believe that they were versatile enough to be used on the Space Shuttle, so I've heard.

ClausB
October 3rd, 2012, 01:12 PM
I've wondered whether the compiler we used was from Honeywell or converted from IBM.

The job page header said:
FORTRAN D SYSTEM TAPE REVISION NUMBER 6.0
and the listing page said:
FORTRAN 200 SOURCE LISTING AND DIAGNOSTICS

RobS
October 5th, 2012, 03:39 AM
My Honeywell training course in 1972 was for FORTRAN D and they used their own compiler. FORTRAN is intended to be a very portable language, so one would use the native compiler for the computer on which it is run. My reason for opting to do my calculations in EASYCODER was that even then our computer had no hardware multiply or divide and the software versions built into the Honeywell compilers weren't that great. In those days writing good routines to do those tasks was a game played by aspiring programmers. Our company required us to use actuarial rounding in our calculations as financial calculations need different consideration from scientific ones when choosing a rounding method, so we incorporated the rounding into our routines when we designed them.

The progressive calculation of Pi that I've written as a demonstration programme for the H-200 doesn't use conventional multiplication or division instructions and wouldn't benefit from them much, even on a computer which had them. Also it doesn't use a return stack as the most basic H-200 didn't have that facility either. Memory was too small and expensive then to waste it on a stack. In fact where a conventional modern programme would use a stack this programme contrives to use a first-in-first-out queue, which is more useful because it is continually looping and taking the oldest data to use in the newest calculations. Top down structured programming with subroutines is a common style of programming now but it isn't the best solution for every occasion. In the days when computers had little brains programmers had to exercise theirs a lot to compensate. The "Go To" instruction didn't die out; it lives on with an assumed name under a witness protection programme in every computer.

Agent Orange
October 5th, 2012, 07:44 AM
My Honeywell training course in 1972 was for FORTRAN D and they used their own compiler. FORTRAN is intended to be a very portable language, so one would use the native compiler for the computer on which it is run. My reason for opting to do my calculations in EASYCODER was that even then our computer had no hardware multiply or divide and the software versions built into the Honeywell compilers weren't that great. In those days writing good routines to do those tasks was a game played by aspiring programmers. Our company required us to use actuarial rounding in our calculations as financial calculations need different consideration from scientific ones when choosing a rounding method, so we incorporated the rounding into our routines when we designed them.

The progressive calculation of Pi that I've written as a demonstration programme for the H-200 doesn't use conventional multiplication or division instructions and wouldn't benefit from them much, even on a computer which had them. Also it doesn't use a return stack as the most basic H-200 didn't have that facility either. Memory was too small and expensive then to waste it on a stack. In fact where a conventional modern programme would use a stack this programme contrives to use a first-in-first-out queue, which is more useful because it is continually looping and taking the oldest data to use in the newest calculations. Top down structured programming with subroutines is a common style of programming now but it isn't the best solution for every occasion. In the days when computers had little brains programmers had to exercise theirs a lot to compensate. The "Go To" instruction didn't die out; it lives on with an assumed name under a witness protection programme in every computer.

Just curious Rob, just how far out did you take Pi?

ClausB
October 6th, 2012, 03:45 AM
The progressive calculation of Pi that I've written as a demonstration programme for the H-200 doesn't use conventional multiplication or division instructions and wouldn't benefit from them much, even on a computer which had them.

What multiplication algorithm are you using? The H-200 does BCD math, right?

Are you taking advantage of the variable-length word size?

RobS
October 6th, 2012, 06:17 AM
My target using a 2k byte memory was the Feynman point, 767, and the programme reached 770 after a lot of head-scratching on my part. I don't specify the end-point; the programme just stops when the calculations in progress overflow available memory. The smallest memory size available in an H-200 was 2k and that was all the core memory I had anyway, which is why I set that target. As I have recently been offered several original Honeywell 4k memory modules I can now consider building a 4k machine. Any more memory than that would need "address mode 3" as "address mode 2" only used twelve bit addresses, but address mode three also provided indexed and indirect addressing and building that in would involve a lot more hardware for which I probably won't have the parts or the patience, so I am still limiting my initial design to 4k and the most basic machine marketed. To answer your question completely I just this moment cleared a path through my workroom and across the desktop (something akin to navigating between icebergs with all the boxes balancing everywhere at present) to find my development PC and rerun the emulator with 4k of memory and very spookily it stopped at 1767 decimal places, exactly 1000 past the Feynman point. Therefore adding 2k gave me another 1000 places, which is pretty good memory usage. I also have the "Pi Factory" algorithm written as a demonstration C programme to run on a PC, which is not optimised for memory usage, so I could take it much further but I agree with Richard Feynman, that it is adequate to "end" Pi with "...999999 and so on."

RobS
October 6th, 2012, 07:21 AM
I believe that a significant difference between the H-200 and the IBM1401 was that the H-200 was able to do both BCD and binary arithmetic. Being a character machine with unlimited word length that meant that one could do either to any number of significant digits as well, which was fun. Also having binary arithmetic meant that one could do address modification. In the most basic model of H-200, which didn't have indexed addressing, that meant that one could index a programme loop through an array simply by adding values to the appropriate parts of the instructions, which was okay until the addresses overflowed by mistake and the carries changed the operation codes :) There is no consolidated multiplication or division in my algorithm because it only calculates one decimal place at a time. The only multiplications required are by integer constants so they are done by the time-honoured process of doubling and adding. Divisions just provide a single decimal digit as quotient with a remainder, so are just done by repeated subtraction. In order to calculate the digits progressively all the calculations involved have to be done simultaneously one place at a time. As binary values take less space than BCD I use purely binary numbers but scale them by ten each time around the loop, so they effectively convert into decimal as they are used, a sort of extended BCD if you like. Only the final accumulator is a real BCD field. This field is necessary because I have to allow a delay of a few digits before printing the top one so that carries can propagate through the answer. This final carrying is the only part of the calculation of Pi that demands right-to-left operations; everything else can be done left-to-right even though it runs contrary to our usual view of arithmetic. One of my reasons for choosing the Feynman point as my target was that passing it successfully proves that the propagation of carries is working where it is most likely to fail.

I do use variable length words in the FIFO queue but that alone wasn't enough to hit my target, so I have added half-byte compaction to eliminate half-byte zeroes. The memory used by the compaction and expansion routines is less than the savings in the queue size, so it was worth doing ... but I still didn't hit the target then. The H-200 has an additional bit, the item mark, on each character and that tends to sit around doing nothing most of the time, so I use it to mark bytes where a half-byte zero has been suppressed. Making the values variable length isn't an enormous saving though as I only ever store remainders from divisions, which are all small numbers by definition. I have put so much memory optimisation into the H-200 version of the programme that it is now difficult to see how the actual calculation of Pi works in amongst all the optimisation code.

Having achieved sufficient compaction in my software I now have to be equally adept at compacting the necessary logic into my hardware as I only have sufficent backplane space for 200 logic boards even though I have almost a thousand boards to hand. It would be very nice to find another H-200 backplane somewhere, even a small one out of a Honeywell disk drive or elsewhere. Even compatible individual edge connectors (single sided 0.125 inch pitch 40 pin) don't seem that easy to find now. Well it wouldn't be fun if it was too easy.

RobS
October 6th, 2012, 07:27 AM
I forgot to mention that the H-200 would take one hour nine minutes forty eight point four seconds to calculate the 1767 decimal places, which would get rather boring as a demonstration. With 4k of memory I think I'd trade in a few decimal places to speed it up.

ClausB
October 6th, 2012, 11:41 AM
Your answers are so thorough that they inspire more questions!

1000 logic boards? Wow. How many gates per board? Transistor logic? How many types of logic board?

Is the backplane already wired with an H-200 design, or do you have to replicate that?

Have you posted pictures of the hardware?

RobS
October 7th, 2012, 03:23 AM
The logic boards hold from six to thirty-six gates each. They aren't from an H-200 but from seven Keytape machines, Honeywell tape drives with keyboards attached for manually encoding data. These were direct replacements for the old card punching machines with little more facilities. Their design dates from around 1969, some years after the original H-200, and they use early DTL ICs for the logic along with transistors for special functions. Despite packing in more gates per board than the original second generation transistorised boards of the H-200 they were limited by still having only 36 pins on the backplane connectors, so even with only eight gates not all the IC pins could be brought out onto the connector for external access. There are two distinct styles to their design. Some boards are general purpose ones with no internal connections between gates for use where all the logic design is in the backplane wiring and others perform very specific functions and have the logic design in the internal connections between the gates. They illustrate very well the way that the architecture of a computer gradually moved from the wiring of the backplanes to the tracks on the PCBs until eventually the backplanes just became a general purpose bus.

I have 84 types of board, some of which will only serve as sources of parts. The two backplanes that I have were from one Keytape machine and I spent hours removing all the existing wiring to get back to bare pins. I have just obtained an electric wire-wrap gun to make wiring up the new design a little easier. What I intend to replicate is the physical appearance, external and internal, of the machine as far as possible (I even have a sample of the original blue paintwork on the cabinets) and the operational and programming aspects, again as far as possible, but the actual logic design will have to be a compromise between authenticity, available components and available space on the backplanes. I will keep to using original Honeywell components as far as possible and only use other components which are appropriate to the era. I really don't want to use an original control memory though, even though one may be available, as they were extremely sensitive to variations in temperature and prone to burning out. This computer must operate reliably in a domestic environment in England (too damp a climate for reliable punched cards as well).

Vintage computer projects vary from dedicated careful conservation of original machines to building replicas using modern technology or software emulators. This project will be fun because it has one foot firmly in the 1960s and the other in the 21st century. If I do manage to complete the machine I will be able to claim that it is the newest 1960s computer in the world.

So far I haven't posted anything but this thread as I intend to put everything on the project website honeypi.org.uk which isn't up and running yet. Designing the website is just another little task that I have to master in my spare time as I was hoping to leave that particular skill to the next generation, so never took an interest in it. I do have an old friend who runs a web-mastering company though, so ...

g4ugm
October 8th, 2012, 05:43 AM
I used a H3200 was that a 200 familiy machine...

RobS
October 8th, 2012, 06:36 AM
Yes, that was one of the series. Our company kept upgrading so I never kept up with what the current machine was called, but I think that after the H-200 we had a 1250 and a 2200. At some stage we moved over to the series 60 and 66 running the GCOS operating system, originally the GECOS system from General Electric which Honeywell took over. If you hunted around in the operating system you could find places where Honeywell hadn't even changed "GECOS" to "GCOS" in the text when they adopted it. The GCOS family were fundamentally word-oriented machines and didn't have the simple style of the series 200 character-oriented machines although they included the EIS feature, the "Extended Instruction Set" which emulated the series 200 at hardware level. I remember an instructor on a training course enthusing over EIS and we couldn't understand why until we found out that he had only just come to Honeywell from working on IBM machines and thought that EIS was a great new feature, not realising that it was actually included for compatibility with the way that older Honeywell machines had been working for years. That in itself said something about the 200 series architecture.

g4ugm
October 8th, 2012, 09:06 PM
I thought to get the S/200 emulation on the L66 you needed a hardware add-on, which was really the guts of a 200 series. EIS was really for COBOL.....

RobS
October 9th, 2012, 03:56 AM
You could be right. By the time we had the level 66 I had moved from programming to analysis and didn't need to understand such things so well, so that was hearsay. Our machine had both capabilities, so I don't know whether they were separate hardware or two aspects of the same hardware. What you got in the box and what you'd paid for weren't necessarily the same anyway. Our engineer once mentioned that one of our machines had a go-faster option which he could activate virtually instantly at the flip of a switch -- if we'd paid for it of course. History doesn't record whether he ever flipped the switch for a while but our work usually seemed to get done on time ... and PC gamers thought they were the first to use overclocking.

As another example the smallest memory configuration marketed for the original H-200 was 2k but I can't find any mention in the system description of memory modules being anything but 4k. The documentation states that the first 4k module was logically divided into the basic 2k and an optional second 2k, but there is no suggestion that the modules themselves were cut in half and all the supporting driver boards were designed to support 4k anyway, so the machine must have had the 4k capability as standard. The smallest assembler for EASYCODER needed 4k, so a 2k machine couldn't even assemble its own programmes. Honeywell envisaged 2k machines as front end processors for larger computers, so maybe they weren't bothered about giving away 2k of unused precious core memory to a good customer with other large computers and the reduced selling price was just a marketing ploy. A strong feature of the H-200 was its time-sharing peripheral handling which meant that it was more suited to being a sophisticated peripheral controller than a number-cruncher, but Honeywell managed to play it all ways. Interestingly the later Level 6 minicomputers were also employed as front ends to mainframes, handling communications with many dumb terminals. The Level 6 series followed the same principle of modularity established much earlier during the design of the H-200. I know because I have a "DIY" DPS6 kit made up of the components of seven such computers all using Honeywell's "Megabus" architecture.

g4ugm
October 9th, 2012, 06:21 AM
There were lots of examples of that type of thing on the L-66. There were the 100/100Mb disks that only used the first 100 tracks and were upgraded by moving a jumper. My favourite was the "gear shift" on the L66/17 (and I think 27 and 37) models.

So the 17 performed like a L66/10 in batch and like a L66/20 for time sahring and on-line TP. The secret was a few lines of code in the dispatcher which disabled the cache. A one line path would make the machine run like a 20 for batch as well. A wonderfull marketing trick. Of course to upgrade you simply changed a link that set a bit in a control word....

The same pracrices continue today. Look at the BROCADE 24 port swith:-

http://www.brocade.com/products/all/switches/product-details/6510-switch/index.page

note the "port on demand" feature. Basically this means you always get a 24 port switch, but they charge you extra to use all 24 ports. IBM have a similar "storage on demand" feature in its SAN. It comes full of disks, you pay when you need them...

RobS
October 9th, 2012, 07:34 AM
Now here's a funny thing. For one brief moment there was a posting from marcelvanherk on this thread. Marcel is the man with the H-200 memory modules and therefore a key person in my project. He subscribed to my thread at my invitation but I suspect that his posting may have been zapped by a zealous moderator, which is quite understandable and laudible, but I hope that Marcel sees the funny side and returns as I would be at a distinct disadvantage without him. Are you still there Marcel?:)

RobS
October 9th, 2012, 08:15 AM
We're getting too far off topic for me now. G4UGM and all things analog? Being unable to tear myself away from the early 1960s I still have a small collection of valves somewhere. I may even still have a thyratron in the garage. It was taken from the "Mark 1 Televisor" that we used to watch the Queen's coronation in 1953. Any use for a 1962 printing of the 1961 third edition of The Amateur Radio Handbook, or is that even further off topic?:)

RobS
November 23rd, 2012, 07:14 AM
An update on my project, now permanently dubbed HoneyPi.

Marcel and I met up and pooled our resources, hardware and skills, so the project is definitely on. We now have enough memory and logic boards for the CPU and also enough switches and button tops to construct the control panel, although some buttons will be slim ex Univac buttons beefed up to the size of Honeywell buttons with a back moulding of clear acrylic. I've made one prototype just to prove that it works. I intend to use the remaining acrylic from the batch to make decorations for the Christmas tree; well, one must keep a sense of proportion.

Currently most of the work is putting together the infrastructure rather than logic. My checks on the PSU capacitors indicate that they are still in good condition after forty years out of use, which is a surprise. Having discovered how many supporting logic boards are needed just to get the core memory working, I am concerned about our shortage of backplane sockets. We only have 200, less than half the number used in the original model 201 CPU, so we may well have to pack the ICs that we are using onto custom-made boards to fit everything in. The memory support logic is the original second generation H200 stuff and we don't want to mess that around more than is necessary. At best HoneyPi is only going to be the illegitimate offspring of the H200, but should be identical performance-wise as we are working to original system timings and specifications as far as we know them.

Timing trials on the logic ICs gave a gate delay in the range 20-25nS, which will make designing logic around the 2 microsecond memory read/write cycle comfortable. We still don't know exactly what the ICs are, although we know their functions, as the Honeywell identifiers, AAAL4, AAAL5, AAAL6, AAFL1, AAVL1, etc are unhelpful but I have noticed secondary identifiers on some made by TI. These are 4295P, 4296P, 4297P and 4298P. I don't know of a 4200 series of ICs coming from TI in the 1960s but maybe somebody else does. Anyway, we know enough about them to use them.

Unfortunately I'm too busy (and probably incompetent) to set up the HoneyPi website at present but will get it under way when we've made demonstrable progress. Meanwhile it's all happening.

ClausB
November 24th, 2012, 04:50 AM
I look forward to your progress.

Are the ICs PMOS? Do they have negative supply voltage? In the early 70s TI made PMOS ICs for their first calculators. Maybe that's the P in your part numbers?

cbc
November 24th, 2012, 05:09 AM
RobS,

Sounds like great progress. It's truly amazing what can be done with enough determination & resources!

I, too, look forward to progress. Maybe a few photos too.

Clay

RobS
November 24th, 2012, 05:51 AM
The ICs use +5 volts and have feedback capacitors back to an intermediate connection point within each gate. We assume that they are DTL. The current levels on inputs point to that. I have schematics dated 1969 which use them and some ICs with 1969 batch numbers on them but that's the only clue to when they were introduced and they probably date from earlier.

RobS
November 24th, 2012, 06:16 AM
Well, this is what's meant by starting from scratch, the main frame of the mainframe so to speak. I was about to give it to a scrap metal dealer when I relented and put all the parts back to start this project.
11075
... and here's my stockpile of original Honeywell components. Also Marcel has contributed the memory components but they aren't shown here.
11076
We are taking photos but they'll have to wait until I get that website up.

RobS
December 7th, 2012, 02:16 AM
Now we're really starting from scratch. One backplane is too restrictive on the design, so I've removed all the components again and arranged to take the frame to a foundry to get a copy made. That will enable us to put the CPU and memory on separate backplanes as in the original H200 design. The H200 hardly qualified as big iron, but it's certainly small aluminium. I would have loved to follow David Gingery's example and done the work myself, there even being a few crucibles in my garage just in case, but there's just too much for me to do already.

We don't have enough sockets to fill two backplanes, but I am considering several measures which will enable the logic boards to be spread across the two. One measure may be to get additional socket cases made by a 3D printing service. Pins can be transplanted from other unsuitable edge connectors to complete the sockets. I already have a stockpile of over 700 wirewrap pins which will do. Also Marcel believes that sockets from Univac machines may be directly suitable, if there are any going spare anywhere.

It would be poetic to use sandcasting, one of the oldest known ways of making shapes, in conjunction with 3D printing, one of the newest, on this project.

MikeS
December 7th, 2012, 07:52 AM
How about a closeup pic of those 'sockets'?

RobS
December 7th, 2012, 08:55 AM
Here's the top view. The connectors are in blocks of five. It might look like ten but each board uses two across. The pins are spaced at 0.125 inch pitch. The break-apart provision in the centre suggests that they evolved from earlier eighteen pin connectors. I think earlier boards were narrower than the H200 ones. Marcel said that the eighteen pin connectors are compatible with Univac but the gap between the pairs is a different width. For the H200 it's exactly four pins, half an inch. If the gap is the only problem then one could put Univac connectors side by side with a half inch gap and let each H200 board straddle two.
11250

RobS
December 13th, 2012, 07:49 AM
Here's a bit, several bits actually, of a Honeywell 200 memory.11299 The picture is rotated 45 degrees to frame up the central core, so the red and green diagonal wires are the x and y axes, the vertical green wire is the inhibit line and the thin red wire parallel to the green diagonal wire is the sense line. That's how I understand it anyway. The quality of the picture isn't too bad considering that the microscope I used is even older than the Honeywell 200, having been bought at a police station sale of lost property by my late father-in-law in the distant past, so I believe. I have some other Honeywell memory planes which have five wires through each core, but they work differently from these and weren't used in the H200.

ClausB
December 16th, 2012, 12:52 PM
Cool micrograph! - from a fellow glider pilot (Schweizer 2-33, 1-26, Grob 103, Blanik L-13).

RobS
December 17th, 2012, 06:12 AM
Appearances can be deceptive. I am no more a glider pilot than Honey Pi will be a real Honeywell 200; both are a matter of creating a convincing illusion. My avatar photo was taken while on a day out with our pensioners' group several years ago. I did get a flight with an instructor though and even took the controls for a while. However, my only other experience of flying was as an RAF cadet in my school days and flying a glider is different from flying aerobatics in a Chipmunk with an engine. The winch launch was definitely memorable though, getting things happening very quickly indeed, just like finding like-minded people on the Internet is.

The backplane is now at the foundry waiting to be copied but it won't be done until after Christmas probably.

RobS
February 27th, 2013, 09:10 AM
I finally got around to setting up the website http://www.honeypi.org.uk/ although there's only a couple of pages on it so far. For the time being if you have any comments about it, especially about my amateur attempt at website authoring, please post them here. When I make a significant update to the website I'll mention it here again.

On the hardware front I've been nursing forty year old PSUs back to life and adapting them to provide all the voltages needed by the core memory logic. Once that's done we can start testing the core memories themselves and find out whether the project is viable. It'll be a lot more viable when the weather gets warmer here.

Somebody told me that many surplus machines from the Honeywell 200/1200/2200 range were bought up by EUR Systems in Mechanicsburg PA and cannibalised for spare parts for their own machines, which they were still using in year 2000. I wonder what happened to them after that, but the fossil hunt will have to wait as we have enough parts to play with for the time being.

ClausB
March 5th, 2013, 02:51 PM
Nice site! Please keep the project going.

Gary Wisniewski
March 16th, 2013, 04:26 PM
The link on this page to the Programmer's Reference manual is actually a duplicate link to the logic guide: http://www.honeypi.org.uk/links.htm

Do you have a copy of the PDF for the Programmer's Reference manual?

I was going to write an emulator using a Raspberry Pi. I know the goal is a total reconstruction, but being able to write EasyCoder and get things up and running from a software point of view would be a good parallel task.

biged
March 17th, 2013, 12:56 AM
Brilliant project! (Mentioned now in the new-fangled gplus, here (https://plus.google.com/u/0/117062486976045682927/posts/ba6xsXtZg2D) and here (https://plus.google.com/u/0/106459182571763212187/posts/5Ta5qTwwyb1))
Cheers
Ed

RobS
March 17th, 2013, 04:52 AM
Mea culpa -- That's Latin of course, allegedly a dead language but not as dead as Easycoder. I've corrected the incorrect link now, so you should find it's okay if you refresh the page in your browser. Thanks for telling me and also the "omg" in the Retro Computing forum. I get that feeling myself quite frequently but it's just a matter of taking things a step at a time and so far we haven't found a reason why we can't succeed -- eventually. So far all that I've produced is the smell of ancient grime burning off of long disused equipment which is experiencing electricity again.

I did explain the reference to Pi that confused you on my website, that the project may be irrational and never end just like Pi, a fatalistic mathematical joke. Although you are contemplating an emulator on the Raspberry Pi our intention is to use an Arduino ATMEGA2560 with an interface to a PC to run tests on the partly completed hardware, but in fact the ATMEGA2560 could easily emulate the H200 and run the control panel all by itself.

I have an incomplete and primitive PC-based H200 cross-assembler, emulator and memory dump programme written in C++ for Borland C++4, itself now virtually vintage software as I bought the Borland package eighteen years ago and still use it. I wrote the software as disposable code just to test my Pi Factory Easycoder programme, but if it's of any interest I could make it available on the website.

I was intending to put the details of the Pi Factory algorithm on the website soon anyway as it is just a mathematical approach to the calculation of Pi designed to work on the simplest form of computer, not even needing multiplication or division capability, which the most basic H200 didn't have. I'll try to add it to the website in the next few days. As it is progressive, outputting digits as soon as they are available, there is no predetermined number of decimal places to which it will run. It just stops when the whole of the available memory is full of partially completed calculations and it can't add any more. That means that it gets slower as it progresses as well, so it is an interesting test of both how fast a particular computer runs it and also how far. It is so undemanding that it could probably be programmed into any of the vintage machines covered in this forum, which might give rise to some interesting comparisons. Of course the original Honeywell 200 only had to deal with one comparison to sell successfully from the outset and the result of that comparison is history.

RobS
March 17th, 2013, 06:00 AM
... 1000 logic boards? Wow. How many gates per board? ...

I finally compiled an inventory of the ICs in my stockpile of Honeywell logic boards. There are over 5400 ICs which provide in total approximately 5000 AND-OR gates, 3000 AND-OR-NOT gates and 1000 flip-flops. That should be enough to build a small computer, certainly something more than a PDP8. Perhaps someone has some statistics on the number of gates in early computers. I just wonder how many of the ICs will have to be transplanted onto new PCBs before we've finished. I have a PCB manufacturer with wave soldering equipment interested in the project, so perhaps we'll need his help eventually, but is there such a thing as wave unsoldering equipment?:)

RobS
March 20th, 2013, 08:08 AM
As promised my website now contains this page The Pi Factory (http://www.honeypi.org.uk/pifactory.htm) which describes the demonstration programme. The Easycoder version with its manic optimisations is shown but there is also a saner version in C++ to assist understanding of the mathematical process used. The source code for that is included in case anyone wants to try something similar on another computer.

rorypoole
April 10th, 2013, 11:01 AM
your Honeywell 200 resurrection project is great, I am working on building a pdp8 straight 8!

MikeS
April 10th, 2013, 11:21 AM
... is there such a thing as wave unsoldering equipment?:)Yes, although it's usually called a blow torch ;-)

If the pins aren't bent and the boards are small enough you can also try putting them upside down into a toaster oven set on broil; a good tap and everything falls out.

MikeS
April 10th, 2013, 11:23 AM
your Honeywell 200 resurrection project is great, I am working on building a pdp8 straight 8!You guys are both nuts, but more power to ya!!! Am enjoying following your progress so far.

RobS
April 10th, 2013, 01:43 PM
I understand that the overheads in a PDP8 were similar to those in an H200, i.e. lots of gold-plated edge connectors and a complex wire-wrapped backplane, if you're planning to build it in the original manner rather than just as an electronic equivalent. Our advantage is that we have over a thousand logic modules with their edge connectors intact but, having checked on the cost of getting new custom PCBs made, about half of that cost appears to go on getting the edge connectors gold plated, especially the way the price of gold is currently. Then there's the silver-plated kynar wire for the backplane and the matter of finding a wirewrap gun, preferably electric for extensive work, with the right size bit for the backplane pins. I've got that side of things covered though. I read somewhere that gold-plated edge connectors were prone to deterioration over time but ours seem okay. Maybe that's because they were removed from the backplanes for long term storage. All in all this project seems to be as much about logistics as electronics.

RobS
April 10th, 2013, 01:58 PM
Yes, although it's usually called a blow torch ;-)

If the pins aren't bent and the boards are small enough you can also try putting them upside down into a toaster oven set on broil; a good tap and everything falls out.

It looks like all the ICs have at least two pins bent. Probably they were inserted by hand during manufacture as I have Honeywell's manual assembly instructions for them. The jumper wires on the boards are the usual giveaway as machine-inserted jumpers tend to have dummy components on them while manually inserted ones are plain wire; at least that's how I read it. For the ICs to drop out during heating I'd have to clamp weights onto them, which I have considered doing if I go in for bulk disassembly. Today I managed to wrestle two reticent zener diodes off of one of the boards. At that rate I'll be an old man before I finish. Come to think of it, I already am an old man so it doesn't really matter.

rorypoole
April 10th, 2013, 04:15 PM
I understand that the overheads in a PDP8 were similar to those in an H200, i.e. lots of gold-plated edge connectors and a complex wire-wrapped backplane, if you're planning to build it in the original manner rather than just as an electronic equivalent. Our advantage is that we have over a thousand logic modules with their edge connectors intact but, having checked on the cost of getting new custom PCBs made, about half of that cost appears to go on getting the edge connectors gold plated, especially the way the price of gold is currently. Then there's the silver-plated kynar wire for the backplane and the matter of finding a wirewrap gun, preferably electric for extensive work, with the right size bit for the backplane pins. I've got that side of things covered though. I read somewhere that gold-plated edge connectors were prone to deterioration over time but ours seem okay. Maybe that's because they were removed from the backplanes for long term storage. All in all this project seems to be as much about logistics as electronics.

I am planing to build a close copy of the pdp8 but using modern transistors on copys of the original pcbs in a copy of the pdp8 straight 8 case, I think why gold-plated edge connectors could deteriorate is if there is contaminants under the gold and damp gets in, it would probably be worse if the backplane pins are not also gold plated, and the board left in backplane and damp

RobS
April 11th, 2013, 02:47 AM
... I think why gold-plated edge connectors could deteriorate is if there is contaminants under the gold and damp gets in, it would probably be worse if the backplane pins are not also gold plated, and the board left in backplane and damp
Perhaps the important point was that they weren't in the backplane as they spent almost forty years in open crates in a garden shed, probably not the serious conservationist's ideal environment. I was scraping the rust off the cases of some of the power transistors yesterday and the wiring on a few boards has signs of verdigris but at least I've cleaned off all the spiders' webs and removed the dead woodlice. Some boards have small electrolytic capacitors on them which look like they've suffered from frost damage, but that's fixable. So far everything not obviously broken that I've tested has worked amazingly. Nevertheless even if our creation looks and behaves like an H200 it is still going to be more like a Frankensteinian monster under the skin. I think I'm definitely earning my stripes as a resurrectionist.

rorypoole
April 11th, 2013, 09:24 AM
my pdp8 will also be a Frankensteinian monster, lol

rorypoole
April 11th, 2013, 12:36 PM
I was working on a badly water damaged commodore 4016, and one power transistor was very badly rusted, I found that socking in a vineger with a bit of washing up liquid, and scrubbing with and old tooth brush every day, the transistor and rusty case screws came up nicely, I then sealed it with wood vanish. you would have to unsolder the power transistors, and 40 year old electrolytic capacitors are likely to unreliable after 40 years of non use and cold, even if reformed, I would love to see some pics of the work in progress on the Honeywell 200 and the old boards before and after.

RobS
April 12th, 2013, 02:12 AM
Actually I'm not too worried about the rust; hopefully it's superficial. Some of the logic boards had mould growing over them; it has a particular liking for the plastic insulation on wires for some reason. I've already tried the washing up water and toothbrush treatment on them along with carefully drying with a hairdryer and they seem quite happy with it without any need to disassemble, but I wouldn't attempt that with the power regulator boards. I did consider painting the power transistors but if so would have used heatproof engine block paint I think, but anyway I'd prefer to give the cases the chance to dissipate heat. I know it's only a small proportion of the total but every little helps.

The only electrolytics of any importance are the Farad's worth in the PSUs and they are bearing up okay so far after reforming, but then they were never left in the garden shed. I'll be using the PSUs as a bench supply during the development so that we know how reliable they are when we come to put it all together. As we have no idea what the total power needed will be there's no point in considering the final design for the PSUs now. The main transformers to hand can handle a kilowatt but I've no idea whether that will be enough. There's also the complication that this is American equipment marketed in Britain, so its design uses a mixture of British and American mains voltages and I have to be careful just connecting up the mains wiring. I've discovered that it isn't that easy to buy ordinary American domestic three pin plugs in Britain but, having found a supplier, I can now be more disciplined about what plugs in where.

When I find the time (!) I'll put a gallery of photos on my website, but my workroom is so tiny and full of shelving that taking photographs with anything but a fisheye lens is pretty difficult. Certainly both I and my colleague Marcel have taken photos of the individual components and I'll try to put some of those together in a meaningful fashion. To photograph my entire collection of H200 components in one go I had to convert our whole living room into a photographic studio but my wife insisted that it be restored at the end of the day, so that exercise won't be repeated very often. She does understand me though. When I gave up the project a couple of years ago and started to write a novel instead she thought I was mad, so which is saner, writing a novel or building a mainframe computer in the spare room? I suppose it just depends who you are. As the novel appears to be one of a trilogy I'm still working on that as well whenever I get frustrated with this project. That's another reason why the photos may take a while coming.

rorypoole
April 12th, 2013, 04:22 AM
be careful, some vintage computers like the pdp8 used a special transformer that is self regulating but is locked to supply frequency not voltage, it is easy to spot is it had a winding with only high voltage capacitor or capacitors across it, and no regulator just some power diodes and smoothing capacitors.
and I cant wait to see your work.

RobS
April 12th, 2013, 05:22 AM
You mean a constant voltage transformer I assume. Yes, Honeywell loved them and they're all like that but the ones that I have are clearly marked for 50 Hertz use, one of the few concessions that they made to our mains supplies. They came out of equipment used in the office where I worked and I'm following the original engineer's manuals for the wiring, so there shouldn't be any problems. There was no other voltage regulation in the PSUs themselves as you say, but in the equipment from which I removed the backplanes there were shunt voltage regulators acting like high power zener diodes which trimmed the voltage to the right level and kept an even load on the PSUs. I'm keeping the same setup for the bench power supply, but that was only for the 5 Volt supply to the logic boards. Marcel's collection of original second generation boards which drive the core memories need 15 and 28 Volt positive and negative supplies as well, so I'm having to improvise all those. I've converted a couple of dual diskette drive PSUs from Honeywell Level 6 computers to provide 34 Volt supplies which can be regulated down to 28 Volts using the shunt regulators. The diskette drive PSUs, which date from the 1970s, used CVTs as well as voltage regulator ICs to provide a level voltage, but of course I've removed the ICs because they're the wrong voltage apart from being outside the project terms of reference at present.

As you can't wait to see my work here's a picture of the 5 Volt regulator screwed up above my workbench. 12746 The regulator is an unmodified Honeywell module and the economy resistors above it, made out of electric fire element wire, reduce the current to a level that the regulator can handle when the output load is light. The meter indicates whether the regulator is operating within a suitable range. This is just test bench equipment though, not a part of the final machine. I haven't fitted the cooling fan yet but it will need one.

rorypoole
April 12th, 2013, 03:30 PM
why is a shunt regulator used? it is not good for the electric bill and makes a lot of heat when the load is low? I have only ever seen them used on wind generates, as they need a load at all times to stop over speed. you work it very neat.
the pdp8 used constant voltage transformers for -15v +10v and +36v for the core memory, I will not be able to find constant voltage transformers so I will use conventional transformers with Linear regulators like the 7810 7915, and split the load across the regulators and transformers, I have a horde of 12v transformers that will do the -10v and +36v, and some others that may do the -15v, this will not be as efficient as the original constant voltage transformers used, and will probably be heaver! the 78 and 79 type regulators are the only ICs I will have in the main PDP8.

what will you use to store your programs on the honey pi? and punched cards can still be found, but I like the idea of using used rail tickets, and they are free!

RobS
April 13th, 2013, 03:35 AM
I'm interested that you consider shunt regulators to be inefficient but CVTs efficient. I was under the impression that CVTs were notorious for spewing out heat and EMR. Regarding the shunt regulators I don't know why Honeywell used them but it is probably, as I mentioned on the programming page of my website, that there are no right or wrong solutions, only appropriate and inappropriate ones and I can only guess why Honeywell's solution was appropriate, so here goes. The CVT in the PSU provided the primary stabilisation of the supply voltage and the shunt regulator mounted in the centre of the backplane completed the task. Being in between the logic boards where the power lines enter the backplane the regulator provided the best possible control of the voltage delivered to the boards, but that probably isn't the whole story. Located there it had two tasks, firstly to compensate for voltage variations caused by cables and dodgy connectors between it and the PSU and secondly to compensate for varying demand from the logic boards. If we assume that the first effect was relatively constant then the major dynamic effect came from the second. The shunt regulator solved the problem by sinking the excess current when many logic boards went idle and the effect of this was to maintain constant power consumption and therefore constant temperature within the backplane enclosure as well as putting a constant load on the PSU. For reliability of electronic equipment constant everything is good as one can easily design for it. Contrast this with a modern efficient computer which consumes varying amounts of power from moment to moment and uses variable speed fans to compensate for the temperature fluctations, or a complex switch mode PSU which is very efficient while it works but then commits suicide when it can't decide how to tackle a situation. That's no problem nowadays when there's always another computer close by to replace the one that's misbehaving, but in the commercial computing world of the 1960s reliability was much more important than efficiency. There are other arguments, such as the fact that a shunt regulator doesn't have to pass all the current for a device like a series regulator and it doesn't reduce the voltage at all when it's not needed to. Personally I'd be more concerned about the CVTs and apparently so were Honeywell. The PSU cooling fan is mounted separately from the PSU chassis and connected to it by a plug and lead, which includes a blocking loop which stops the PSU working if the fan is left unplugged, whereas the regulators were just plugged into the backplane along with all the other boards.

Anyway I don't think 1960s American equipment was designed with efficiency at the top of the list of requirements. As an example, the lights in the Honeywell display panels had current running through them all the time, just not enough to make the ones that were supposed to be off glow. Someone mentioned that they remembered that the display on the H200 seemed to react to signal variations much faster than those on other computers, which was probably for this reason. Other benefits were that the transistors controlling the lights only needed to sink part of the current to turn them on and the lights never cooled down so much and therefore lasted longer, another example of constant being a good thing. I reckon that in total the lights on an H200 panel consumed around 7 Amps at 14 Volts, that's almost 100 Watts, when they were all on, which actually only happened during initialisation, but they must have consumed a good proportion of that figure when they were all "off" as well, so a few amps sunk by a 5 Volt shunt regulator won't be a big issue. Rather than worrying about power consumption one should just use the computer in the winter and save on the central heating bill. The branch offices of the company where I worked had Honeywell Level 6 minicomputers which made good room heaters as well as doing the office work but the staff had to keep the windows open in the summer -- and those machines had complex multimode switch mode PSUs.

Regarding storage, I am hoping that my Dataplex machine is still serviceable. It has two magnetic card drives which use big cards the same size as punched cards, each card having 50 tracks with 256 bytes per track, making 12.5k bytes per card, a forerunner to the floppy disk drive. The Dataplex uses all 7400 ICs, the original full power series, not even the LS series, so it is reasonable technology to use with the H200. Its memory uses long serial shift register ICs which cycle continuously, so the machine just has to wait until the right byte comes around in the register cycle each time like a virtual disk drive. At least the machine was designed, patented and built by a British company and it has very few light bulbs and no shunt regulators or CVTs so far as I can remember.

RobS
April 13th, 2013, 03:57 AM
...this will not be as efficient as the original constant voltage transformers used, and will probably be heaver! ...

Someone offered me switch mode PSUs to use in the H200 in place of my CVTs but I pointed out that I need their weight inside the cabinet to stop it falling over when a backplane is swung out for maintenance. That's what you might call well balanced design.:) The biggest item of ballast will be the 1 kilowatt autotransformer used to provide the 120 Volt AC supply. With that feeding current into the CVTs I can say goodbye to any thoughts of efficiency.

RobS
May 1st, 2013, 05:23 AM
Somebody told me that many surplus machines from the Honeywell 200/1200/2200 range were bought up by EUR Systems in Mechanicsburg PA and cannibalised for spare parts for their own machines, which they were still using in year 2000. I wonder what happened to them after that, but the fossil hunt will have to wait as we have enough parts to play with for the time being.

Someone kindly tracked down the chap who rescued a big pile of components from the machines that used to be at EUR. He has ten times as many logic boards as us and over 35 backplanes, but plans to sell them as scrap. Well, that's his right of course and understandable, but if he doesn't change his mind our project will continue to rely on European resourcefulness rather than American resources. The shipping costs across the pond would be appalling anyway but fingers crossed chaps. Of course, if anyone Stateside is thinking of building an H200 I know a man ...

cobracon
May 1st, 2013, 04:22 PM
What was the scrap price on the parts?

RobS
May 2nd, 2013, 01:16 AM
I've only managed to get one email out of the man so far and don't know whether he's willing to correspond any more, so details are sketchy. He scrapped part of his collection around the year 2000 and bearing in mind the escalation of the price of gold since then he believes that sitting on the remainder for another couple of years would be worth his while. My colleague Marcel did some rough calculations and based on 10,000 logic boards each weighing 100gms estimates they might be worth $10,000. However, without an inventory of them we wouldn't be able to determine which were of interest to us and the man has also dumped all the documentation for them, so we can't see much value in them for us except as sources of components, i.e. ironically everything except the gold on the PCBs! The backplanes are more difficult to assess and unfortunately the man hasn't mentioned how much he got for the ones he's already scrapped. He claims that the contacts in them have small dots of gold at the contact points, which must be very small as I've not seen them in the ones in my possession, but the sockets are very deep. However, there are 5760 contacts in each backplane and he has more than 35 of them, so it all adds up. Apart from the contacts a backplane contains about 9 pounds of aluminium alloy. How one values a backplane on that basis I don't know, but I doubt that the value is significant compared with the cost of shipping a 30 to 40 pound package across to England. He hasn't even suggested a price as he's sure that gold prices will continue to rise steeply in the future. As the price of gold is an indicator of the amount of panic in the financial world his view of the future seems pretty depressing to me. I was hoping that we'd seen the last of the financial meltdowns since the dot-com collapse in 2000 decimated my own retirement investments, which have only now barely recovered.

As I suspected, this project is just as much about putting together people as putting together hardware.

rorypoole
May 3rd, 2013, 07:25 AM
it is very sad that the guy scrapped part of his collection and dumped all the documentation, maybe with some luck you could save some of the logic boards and backplanes, for your Honeywell 200 replica

RobS
May 3rd, 2013, 10:01 AM
We only expect to need one more backplane and we're still hoping to do a deal for that. Someone near Harrisburg PA has offered to arrange collection and shipping for us if the deal goes through, so that part is covered. The logic boards probably aren't worth the shipping cost even if we told him to break off the edge connectors for the gold content and ship the rest to us for the components to reduce his asking price. We're going to have to design our own boards for some of the logic anyway, so we could make use of loose components provided that they were similar to the ones we already have, which we don't know at present. If they were then we'd still really need some kind soul stateside to strip the components and send just those to us to reduce the shipping weight. Well, I did say on the website that there was a reason for putting ".org" in the domain name, because I reckon in the end this machine will just be held in trust by us, not owned outright by anyone. So far as authenticity is concerned, we don't have the detailed design for the original machine, which was second generation not third anyway, so I don't have any qualms about using custom made reproduction boards for our own design where necessary, especially as this will make the machine more compact than the original. I am hoping that by and large the electronic components will all be 1960s Honeywell original though, at least in design if not actual date of manufacture.

RobS
June 14th, 2013, 09:47 AM
The good news is that we did the deal on the extra backplane and now have it on site in England. That gives us a total capacity of up to 360 logic boards, but I dread to think how much juice that many would drink. With the socket shortage problem solved I can turn to other important matters. I also now have the five regulated voltage supplies needed by the core memory drivers installed on my workbench and can start testing the individual boards, but not yet. My wife and I are about to head for the south of France to spend a week cruising up the Rhone. There are other things in life apart from vintage computers and I need an excuse to get out of my workroom.

BobA
September 2nd, 2013, 05:33 AM
This is exciting. I used the H-200 at my first job in 1978. Yes, 1978. It was a high school co-op job at my city's Dept. of Data Processing. I guess they didn't have much of a budget for buying new equipment.

Computers were so much more physical then. I absolutely loved the front panel with all the illuminated buttons, I got to load and unload disk packs and magnetic tapes, and punch IBM cards and feed them into the reader.

I was less enamored of COBOL and RPG.

- Bob

RobS
September 3rd, 2013, 08:11 AM
We now know that machines from the H-200 series, maybe 1200s or 2200s, were in use right up to year 2000 and it was only the millenium bug problem that retired them even then. Apparently up to the last they were very reliable and only needed the air filters cleaned and worn out fans replaced to keep them chugging along forever. I am told that even the chief designer of the H-200 wasn't aware that they were still in use for that long. If this project achieves nothing else it brought together the chief designer's daughter and the man who was possibly the last maintenance engineer for these machines, one of them with the original design proposals stored in her basement and the other with a graveyard heap of components in his garage. That must have been an interesting conversation. I've always claimed that this project is as much about the people as the machine itself.

I am told that the chief designer of the H-200 used the word "elegant" a lot. I think it sums up the H-200 in many respects and reflects the views of others that I've read in this thread.

I didn't like using COBOL on the H-200 much. (or was it a 1200 by then? Probably.) "Elegant" was never really a word to describe COBOL, but it was a practical language for its time. For a long time I wondered why the words used in it were always the longest possible, like "PERFORM" instead of "DO", "VARYING", "ENVIRONMENT", "CONFIGURATION", etc. Then I realised that it was designed to be a self-checking language in that any mistyped or misplaced word would most likely be meaningless and cause a compiler error. Contrast that with a concise language where virtually anything typed would probably compile into code which did something, even if not what was intended. However, it could be annoying with the long turnaround time for batched overnight compilations to discover that one's programme had failed simply because one couldn't spell a particular long word correctly. The very first COBOL programme that I wrote on my training course had just two errors, or rather two occurrences of the same error, in it and I felt at the time that I wanted to take my case to the court of appeal. Grace Hopper maintained that she wanted a programming language close to English and I maintained that in English "HIGH VALUES" is two separate unhyphenated words! We don't mind Americans adopting a modified version of our mother tongue up to a point, but there is a limit. So much for my view of COBOL.

If anyone is wondering how the construction work is going, there's a lot of groundwork to do before anything interesting happens. At present I'm wiring up hundreds of power connections for the second generation memory driver boards, some of which need five separate supply voltages to work. My Dutch colleague Marcel is heading for the States on a business trip in a couple of weeks time and plans to visit that chap in Pennsylvania with the mountain of components in his garage, but even for Marcel there's a limit to how much luggage he can carry home. That said, last year he did turn up at my home with the entire memory system for the H200 in his rucksack, so who knows. At this rate, by the time this computer is finished its parts will have clocked up so many air miles that it will be able to pay its own visit to the USA.

Chuck(G)
September 3rd, 2013, 08:40 AM
To be fair to COBOL, most if not all, dialects had some shortened word forms, such as COMP for COMPUTATIONAL.

But the length of the words was never a serious issue back in the day. Coding was a small part of the program development process. Users often imposed more Draconian standards on themselves--I recall a government COBOL project where variable names were highly codified--and all about 30 characters in length.

Terse languages can be very hard to read. Glancing, for example, at a LISP program usually does not immediately reveal its function. APL can be very difficult to parse mentally.

I recall that my first PL/I program run on an S/360 produced more pages of diagnostics than there were statements in the program. When the I/O clerk handed me the thick listing, I immediately wondered if he'd forgotten to burst someone else's output from mine.

facattack
September 21st, 2013, 05:03 AM
http://www.starringthecomputer.com/computer.html?c=48

RobS
September 22nd, 2013, 02:27 AM
http://www.starringthecomputer.com/computer.html?c=48
I have the DVD of Billion Dollar Brain by my desk even now. It has been a valuable source of images of the H200 and contributed to the accuracy of the pictures on my website. My comments about Karl Malden's efforts as an H200 operator in the film are already on the StarringTheComputer website.

My globe-trotting Dutch colleague Marcel has just taken time out from a business trip to Boston and Montreal to visit Harrisburg PA and pick up some more circuit boards there. We don't need them as such but need the original transistors on them to build other boards. Other commitments have taken me away from building HoneyPi recently, but I am currently constructing a relational database to record all the backplane connections as I install them so that the design is fully documented. We are following the outline organisation of the memory unit as in the Honeywell documentation but have to plan out the detailed construction ourselves, so keeping our layout documented is important.

RobS
October 3rd, 2013, 02:01 AM
Here's some evidence that the Honeywell 200 was trendy in its time. Apparently one was used by Contact, a New England computer dating service in the early days of that activity in the 1960s.
http://blog.modernmechanix.com/boy-girl-computer/

dtuomi
December 12th, 2013, 02:20 PM
Hi Rob,

Ironically this is my first post on this web forum. I was actually looking around the web for info on the Honeywell and stumbled upon this thread and your website. I'm a little too young to have known any operational H200's, however I have a special place in my heart for them. When I was a teenager in the 80's, I was given the control / operator panel of the H200 as a gift from a friend's dad who worked on decommissioning computers. It's a neat thing with big plasic buttons and lights and stuff. Anyway, I noticed earlier in the thread that you were going to attempt to recreate one. I still own the control panel, although it has sat in a garden shed for many years now. Last time I had it out it was still in pretty good condition. When I was a teenager, I even could light up it's lights (with a 9volt battery), so I know most of the bulbs work. Anyway, I'd like to see it go to help your project, if possible. Please contact me off the thread.

David

ClausB
December 28th, 2013, 06:33 PM
What a wonderful and generous offer! Did you accept it, Rob? Will you post pictures when you get it?

RobS
December 29th, 2013, 03:25 AM
I'm waiting for David to lay his hands on it and send photos, but yes it is a wonderful discovery and having it would save a lot of time on the project. There is just the small matter of shipping it from California to England though. I was fortunate that someone called in a favour to get that backplane shipped from Pennsylvania cheaply earlier this year but this operation could be a bit more costly. Anyway, it will be some time before we need the control panel, so there's no hurry.

I've been working on the project for a year now and I intend to expand my website to document progress early in the new year, but first I need to make some progress worth reporting. So far the work has been on providing bench power supplies and power buses on the backplane and there isn't a single bit of logic installed yet, but now I have all the necessary supply voltages present and have tested and repaired the timing logic, so come the new year with power and timing signals in place I will be able to start on installing and testing the memory unit components.

Being pedantic about the project infrastructure I am currently working on the relational database which documents the design of the backplane wiring for future reference. I was working at this on my laptop while simultaneously casting one eye at the TV and flicking through channels for something to watch when I coincidentally ended up watching Billion Dollar Brain, the film which features the H200, so I was actually viewing the real H200 control panel in operation while designing the wiring layout for the machine. I noticed that there weren't that many lights flashing on the panel in one scene and concluded that a very small programme was running at the bottom of memory. Personally I would have written something that used the entire memory to provide a better visual effect, but there we are. If the project is a success then I may yet get the chance one day.

Happy new year to all those taking an interest in my activities.

g4ugm
January 1st, 2014, 11:48 AM
If the picture is still there this is interesting:-

http://stockton.craigslist.org/sys/4203505606.html

RobS
January 2nd, 2014, 04:46 AM
Yes, it is interesting. Assuming that it is accurate in the detail then the H120 had only three logic drawers compared to four in the H200. Their colours suggest that one was used for the CPU and the other two for memory. I understand that the H120 used IC logic, probably similar to the ICs that I plan to use, which would account for the CPU taking up less space than in the transistorised H200. My intention is to install the CPU in a single drawer, so this picture is a good omen. Despite physical similarities between my design and the H120 my machine will be an H200 as I am working to the functional specification for that machine. In particular the H200 had a faster memory cycle time. This extract from a 1965 magazine advertisement mentions the differences between the two.
16650

g4ugm
January 2nd, 2014, 08:51 AM
Glad it was of interest. I saved the picture as well... I only ever say a H3200 which I think was bigger. I think that had memory in narrow cabinets....

RobS
February 3rd, 2014, 07:36 AM
Here's some evidence that I am making progress with building the memory for the project, even though my progress doesn't include updating my website yet. 17102

The lower trace is the negative-going timing pulse for a memory write and the upper trace is the current from a memory driver circuit during a complete read/write cycle. The current flows forward through the core winding during the read cycle and then backwards during the write, or at least it will when I am confident enough to connect up the core memory itself. This proves that at least some of the salvaged logic boards are still working and that I've connected them together correctly. I am currently checking that the address decoding logic is always selecting the correct combinations of driver circuits, which is a long job when done by hand with a scope.

RobS
February 27th, 2014, 08:19 AM
Today I made real progress with the memory unit. Having wired in two of the nine sense amplifiers I detected pulses from them when the unit was cycled. Deselecting either X or Y drive current made them disappear, so they must have been coming from cores flipping as they were alternately read and written. This is the first sign that there's any chance of getting the memory working, so it's an encouragement to get on with the rest of the work. Okay, so I've only tested four bits in an 8k byte memory so far, but it's a start.

Fortunately the circuit boards for the unit, which were salvaged from a scrap heap decades ago, are almost all working with only the odd component needing replacement so far. The key issue is the condition of the core memory modules themselves though.

For a short while I tried installing all the boards so far in use at the same time to see how my power supplies coped. From the results I think they'll need to be upgraded soon. I'll need some fans on the test bench as well to run any prolonged tests. This old technology really soaks up the power.

Graham Skan
March 19th, 2014, 08:25 AM
RobS - I see that you are working on memory set-up. I remember doing that and I think that I have (somewhere) a couple of UK-produced booklets on the subject. One is for main memory and one is for control memory. If you think that they could be useful, let me know and I'll try to dig them out and get them to you.

Alan Jardine
August 2nd, 2014, 05:51 AM
The visual style of the H-200

Rob S

Later models in the series (the Model 2200 and Model 4200) broke away from the low-boy style of the earlier models, though they still used the low logic cabinets for peripheral control units. The 2200 had a tall-boy style (as did the optional 1100 Floating Point Unit). The 4200 began to look a bit like the IBM 360.

Alan Jardine (just practising!)

Alan Jardine
August 2nd, 2014, 06:34 AM
Yesterday, I read Rob's article on his HoneyPi project in the current issue of the Bulletin of the (British) Computer Conservation Society. I made contact with Rob, we swapped some H200 information and I decided to sign up here.

I was employed by Honeywell from 1965 to 1974 and worked almost exclusively on the Series 200 / 2000 range of computers. Eventually, the Series consisted of the Models 120, 125, 200, 1200, 2200, 3200 and 4200. (There was a Model 8200 but it was a hybrid of the 200 and 800 architectures. I don't think any were installed outside of North America.)

I thought I'd share what I remember about the Series 200 in here before my own "main memory" fades. If anyone has a particular question, I'll try to answer.

Regards,
Alan Jardine.

RobS
August 2nd, 2014, 08:22 AM
Yesterday, I read Rob's article on his HoneyPi project in the current issue of the Bulletin of the (British) Computer Conservation Society.
If anyone wants to read the article the bulletin in accessible here. http://www.cs.man.ac.uk/CCS/res/res66.htm Note that my project is not one operated or funded by the CCS; they focus on British computer technology but the editor liked the article and included it. I've been busy with other things this summer, so haven't had any progress to report.

ClausB
October 23rd, 2014, 12:52 PM
I just got a H200 FORTRAN D manual! This appears to be an earlier version than the 6.0 I used in 1975 to learn programming. I have not seen this on line in PDF form. Has anyone? If not, shall I scan it?

2113621137

tingo
October 26th, 2014, 10:44 AM
If you can't find it on Bitsavers (or elsewhere online) you should definitively scan it.

RobS
October 27th, 2014, 04:28 AM
I was using H200 FORTRAN D in 1971. That software is most unlikely to exist any more, much like everything else connected with the H200.

By the way, I noticed that someone has registered the domain name honeypi.co.uk, very similar to my own. The spooky thing is that he has the same name as me. His website is about holidaying in Devon, England though. How's that for getting off topic?

billdeg
December 7th, 2014, 11:12 AM
what manuals are you missing that are not elsewhere already other than H200 Fortran? 197x's would really be well past the H200's heyday. The H200 was replaced by Honeywell with newer models into the late 60's.

I just found in my library a nice set of product one-sheets and a comparison between the IBM 1401 - H200. Also, an upgrade path doc that describes why one should not replace an IBM 1401 with a H200. Rather the doc describes how one could upgrade a 1401 into the H300 or H800. I.e. the H200 is a replacement without ability to expand any more so than the 1401, so why bother. I can research and post my take of a typical H200 system and correctly configured peripherals that would work together. I see from your site there is a bit of speculation as to what the peripherals would be. I have more on the H800 than the H200, but I have enough to get their place in the mid 60's compared with IBM, etc. You may already have all of this info, I don't mean to assume anything. I just like to do research and would be happy to help.

One last little thing...I think your control panel is a hair too tall. The actual was thinner than your mockup.

Bill

RobS
December 14th, 2014, 03:59 AM
what manuals are you missing that are not elsewhere already other than H200 Fortran?
What do I know that I don't know yet? That's a philosophical question that defies an answer, I think, but my head is already spinning with such problems and they are outside the scope of this thread. In practical terms the engineer's instructions for setting up the timings of the core memory would be a great help at present and I would dearly love to get a copy of the assembly listing of the Easycoder A assembler in order to reproduce the original package, but otherwise anything that anyone might find is bound to be of some historical interest. Send me a private message with more details outside the thread to explain what you have if you like.

I worked on a purely Honeywell site as our company bought its first computer at the height of the H200 sales campaign and we had no legacy interest in IBM, so for us it wasn't a question of migration. Also our software needs were so specialised that we had to write it all in house and commercially available IBM-compatible packages were of no interest. Our expansion path led smoothly through the H1200 and H2200 into the series 60 range acquired from GE and the subsequent management decision to migrate to IBM decades later did us no favours as there were still no commercial software packages available for IBM machines that really met our needs. For this reason my only experience of IBM mainframe technology dates from the time when it was looking antiquated and being replaced by networked pc-based server technology. Understandably my interest centres on the H200 alone and comparisons between it and the 1401 are outside my scope, but others may find them interesting.

Regarding the peripherals, my website refers to the impractibility of reproducing genuine H200 peripherals rather than questioning what they were. I know of someone who owns a Honeywell tape drive from the era and his problems with installing it and getting it working are significant. I sent him some spare parts that I had but personally I'd rather just focus on the CPU.

I never encountered the H800. That was more of a number cruncher than the 200 series, which was better suited to our data processing needs. That said, we used the 200 series to do pretty complex actuarial computations from first principles and the small programme on my website is a demonstration of how a very small H200 could tackle significant tasks of that kind despite not being designed for the purpose. In fact my computations of actuarial tables on the H200 identified misprints in the official books of tables published for use with desktop calculators. That was amusing as our actuarial department made the comparison to confirm that I'd got my algorithms right rather than to check the official tables.

I haven't done any work on the project for about nine months but now that the cold weather has returned I probably will as the circuits are less likely to overheat and they'll help to warm up the house.

RobS
December 14th, 2014, 04:25 AM
One last little thing...I think your control panel is a hair too tall. The actual was thinner than your mockup.
My mockup pictures were based on available images with their inherent perspective problems and Honeywell's own assembly diagrams held in our national science archives, which probably weren't to scale. Apart from that the scale was determined from the pushbuttons used as I have actual examples of them in my collection. Despite my best efforts I never did manage to reconcile all these sources of information to each other exactly and publication of my attempts was a ploy to get anyone who knew better to tell me, so thank you. One very time-consuming task was getting all the text on the panel looking authentic, so I hope that doesn't merit any criticism. One little detail was that in earlier machines there was a button labelled "Central Clear" whereas later the same function was apparently performed by one labelled "System Clear". On available images of actual panels it is very difficult to see which wording was used but I'm pretty sure that it was the former. I am still hoping that my contact in California does have the genuine article in his possession so that my deliberations about the panel are academic.

billdeg
December 14th, 2014, 05:08 AM
Well I think this is an awesome project. The key is to just move forward, you can always circle back and change things later.

I will scan some info I hope you and anyone interested might find useful. I will post when I have something online.

The B-200 as I read recently came with the option as a line item to purchase IBM 1401 emulation software. Sounds like you are saying in your case this was not needed.

Thanks for sharing and nice site!

billdeg
December 14th, 2014, 07:28 AM
Here is a link to a set of docs I think you'll find useful:
http://vintagecomputer.net/browse_thread.cfm?id=589

RobS
December 15th, 2014, 06:15 AM
Here is a link to a set of docs I think you'll find useful:
http://vintagecomputer.net/browse_thread.cfm?id=589

Thanks. They are very interesting. At the date of this particular tender the recommendation to use the H200 machines only as front end communication devices would have made sense. Initially the H200 was intended to be used as either a front end peripheral controller in a large system or the solitary processor in a very small system, but the design was basically extremely modular with as much of the peripheral control as possible outside of the CPU, so replacing the CPU at a later stage wasn't a big deal. The tender quotes for type 201 CPUs, which were the earliest and simplest, so it would appear that the subsequent 201-1 and 201-2 CPUs, and also the 1201 and 2201 models, were not available yet, hence the mention of a possible revision of the recommendation later.

The tiny H200 punched card installation at our site, shown in a photo on my website, had a type 201 CPU, which was easily adequate for the purpose intended. We used this system for about four years as a direct replacement for an electromechanical tabulator, but in fact in that time we developed many new business facilities that the tabulator had never provided. I even managed to write software to compute the optimum contribution level for a complete corporate pension fund, one of our financial products, using just 4k bytes of memory. Our remarkable success with the H200 convinced the company's directors to invest in a much larger H1200 mag tape system and after that we just kept expanding. That was really the threat that concerned IBM, that the H200 could enable Honeywell to put their foot in the door and never leave a client site.

Even with that tiny system illustrated on my website Honeywell provided us with both a resident software developer / computer operator, who is actually in the photo, and also a resident field engineer. In fact the field engineer stayed with us for many years and used our office as a base for visiting other sites in the area. Therefore the claims made about support in the DuPont tender were well founded to my mind. On my website I emphasise that the H200 experience was about the complete service provided, not just the machine itself, so the project is a tribute to all the people involved as well as the hardware, documentation and training aids. It was a smart looking machine as well, so they never missed a trick.

RobS
December 16th, 2014, 02:55 AM
This particular posting is veering off topic, but I think you'll want to read about it.

Earlier I mentioned that someone else had registered the domain name honeypi.co.uk. I have now been in correspondence with him and the explanation is quite weird. He is actually a bee-keeper and was planning to build a device for continuously logging the temperature and humidity within his hives using a Raspberry Pi computer, hence his domain name. That would be understandable except for the fact that we both personally have the same name and knew nothing about each other's domains! The fact that this other Rob S. used to operate an ICL 2966 is just the icing on the top. (The 2966 appears to have been a disk drive, so I need to ask him to clarify what he meant.) The link to the website for the holiday cottage that I mentioned previously was accidental. This is clearly a reminder that if anything important happens we shouldn't just post it on a website but also tell it to the bees.

elpirata
May 8th, 2015, 09:47 PM
I have had a liking for the Honeywell 200 ever since I saw Billion Dollar Brain years ago, anyhow on the BBC iPlayer right now on the BBC Parliament Channel you can see a program called "Sixty years of swing", around 9 minutes in there is a part from election night 1966, where Cliff Michelmore (memba him?) is describing the operation of the H200 they were using in the studio to crunch the numbers. great to see it operating - the past comes to life :)

RobS
May 11th, 2015, 05:53 AM
Thanks for that. I'll try to get a copy of that clip from the programme.

I haven't worked on the project for a year now but another former Honeywell field engineer has contacted me just recently about his stash of stuff and most importantly he still has an engineer's reference manual which contains the instructions for adjusting the memory unit settings and he has sent me a copy of those pages. I would get back to work on the unit but my tiny workroom is now gridlocked with junk, so I am currently planning to install shelves in the loft to take the overflow. That done I'll have a bit of space to continue work.

There's still no confirmation from my contact in California about the existence of an original control panel as depicted in that TV clip, but he has also been doing other things, mostly earning a living. Ah, those were the days, when people paid me money for staying busy all day. It's a long time since that's happened -- getting paid for it I mean.

I have recently applied to invest in a local solar energy farm a few miles from here. If successful the return on my investment will pay for not only the extravagent quantity of electricity consumed by this power-hungry beast but also for other incidentals, like shipping stuff a third of the way around the world from California if I'm lucky. As I will effectively be consuming the electricity from the national grid generated by my own investment in solar panels I will be able to claim that my project is carbon-neutral, at least for the next five years.

KevP
November 10th, 2015, 03:30 PM
Hello. I think the project to re-create an H200 is fantastic. I worked on an H125 in the H200 series at Courtaulds in Manchester for 5 years (late 1967 to early 1973) before going up the ladder. I loved that H125, which was the start of a 40 year career in computing.
A pal is currently on holiday in the usa and is willing to bring back that H200 console as luggage to save shipping costs. Any sign of it being available?

RobS
November 11th, 2015, 12:40 AM
Hi Kev,
Yes, the control panel has now been spotted in my contact's parent's shed, so it definitely exists. He lives on the outskirts of Los Angeles but I don't know where his parents live. If you can give me an idea where your friend is and for how long then I could contact my chap about this offer to see whether there could be an opportunity. Regardless of the outcome thanks for the offer.

I think the H120 and H125 may have been the models that used early integrated circuits in place of transistors as the central processor cabinets looked smaller, holding only three racks instead of four like the H200. If this is so then my machine will be more like these models as I have those early ICs in large numbers. The memory unit is made from genuine H200 circuit boards though. If you have anything at all from your time working on the H125 then it may be of interest to me. I don't even have any printouts from my days working on the H200.

I haven't done any work on the project for almost two years now, but I am just preparing to start again. I turned the power supplies on a couple of days ago and was rewarded with the smell of dust burning on the hot components. My temporary bench power supplies don't provide enough current to operate the complete memory system, so I am considering adding booster batteries to them. The batteries will provide the extra current during test runs and then recharge from the power supplies between times. There's no point in my getting the components for a proper 1960's style mains transformer driven PSU until I know what the full load will be and the dimensions of the enclosure, so for now I'm using makeshift testbench PSUs. Nevertheless even these only use 1960's technology. With all the power being consumed I also need to add cooling fans to the memory. Once I've installed all the inhibit drivers the power consumption will rise about another 200 Watts.

The inhibit windings in the memory prevent a "1" being written to selected bits to form the required byte. To achieve this each inhibit winding passes through every core in an entire plane. Therefore in my 8k memory it goes through 8192 cores, which create a substantial amount of inductance. To overcome this inductance and form a correct pulse waveshape the drivers switch a relatively high voltage through series resistors to create an approximately constant current. The result is that to write all zero bytes to the memory about 200 Watts is burned off in those resistors. When I designed the backplane layout I took the precaution of positioning the inhibit drivers at the top so that the heat wouldn't affect any other components. However, H200 backplanes swivelled out of the cabinet for testing instead of sliding, so the memory unit is currently mounted on its side during construction and testing and my layout for normal operation isn't so effective. I need to place cooling fans directly adjacent to the inhibit drivers to draw air across them sideways. I have also bought an infrared thermometer to check for hot components when the unit is running. Spare parts are a distinct problem obviously, so I'd rather not abuse the parts that currently work.

I was wondering about the precise procedure for adjusting the memory to get it working properly as there are numerous variable elements provided in it to compensate for the variations in core memory manufacture at that time. Fortunately a former Honeywell engineer has contacted me and he still has a copy of the H200 engineer's reference book, which contains the memory adjustment procedures. I now have a copy of these from him, so that's another space in the jigsaw puzzle filled.

Building this machine is just a pastime for me when I have the time, so I am not hurrying to get the work done. The important thing is that I am collecting together in one place all the things needed to do it. The stuff that I have is all at least 45 years old, so a few more years won't affect it much.

KevP
November 14th, 2015, 01:29 PM
"... so a few more years won't affect it much." Hahaha yes, indeed

Aaargh my pal has had to come back to the uk early, so I'm afraid that we've missed the boat, erm plane. He lands at Heathrow tomorrow morning. Sorry about that. However, he goes over there twice a year ish .... usually to places on the east coast Could it be a good idea for you to progress locating the control panel in the meantime, ready for his next trip some time next year? He lives in Aldershot, but travels a lot in the south, with just rare trips up here to the north, when he invariably overnights at my place.

Regrettably, the only thing that I still have from those days is a short strip of mag tape with the data visible! It was taken from a damaged portion of tape that had been chopped from the beginning a 1200 ft reel. One of the Honeywell engineers developed it with magnetic mud, much to my astonishment and excitement. It seemed magic at the time. I sellotaped it onto the reverse (blank) side of an 80 column punched card, with both to be saved for posterity. I'll dig it out and then post a photo of it.

Hot Rod Ron
December 15th, 2015, 03:29 PM
Rather than read thru all of this thread I'll be direct. How is the project coming? I was an Technical Engineer for Honeywell for 16 years starting in 1978 working out of Orange County California. That is what they called us instead of just repairmen. I cut my teeth on the 200 and all of it's peripherals. Later on I worked on the 2000 series stuff. When I left I was working on the level 6 stuff and It's very first personal computer they put out which was built by Zenith. It was an old XT pc with 57 screws on it's lid. It was sold to the military so it had to be secure.

martik777
February 8th, 2016, 06:13 AM
Your project brings back some wonderful memories. I worked on an H1015 in Vancouver, Canada between 1974 and 1979. The attached photo is me in 1974 working as an operator. Later I moved into programming using cobol and easycoder.


The 1015 had 96k CORE memory (approx 10feet long), 5 tape drives, 2 disk drives, a card punch/reader and a paper tape reader/punch. The console was simplified compared to your rendition due to the presence of a typewriter style input console. I still remember the card boot cmd sequence (m/rdr-r1) and many of the easycoder op codes. The tape sorts were entertaining to watch!

The only info I could find on the 1015 is: http://alegion63.tripod.com/bob/id6.html I am pretty sure those removeable disk drive platters were 20MB, not the 2 or 3MB mentioned in the link.

Best of luck with your project!

g4ugm
February 9th, 2016, 08:01 AM
I am also sure those are 20Mb. We had some on our H3200. I think we had 9 drives but only 8 could be online at any time. There was an extra drive on the string so you could change disks and then flip a switch to make the drive available.

RobS
February 9th, 2016, 09:55 AM
Hi guys,

I'm still lurking around although the project isn't moving much at present. I'm just trying to clear other things up so that I can get back to it soon.

My company worked its way right through the Honeywell product line over the years, so I've been around quite a few models but moved further from the hardware and even software during my career. In fact at one stage I worked in a team where we insisted that nobody could even mention computer systems as we were trying to get people to do pure business analysis and even the business staff tended to think in terms of the computer systems that they already had instead of what they really needed.

I remember the machines with the removable disk packs though. Someone left a couple of packs with all the accounting files on the top of a machine cabinet overnight and during a storm rain dripped through the ceiling into the convenient funnels in the top. In the morning the accounting files were goldfish bowls because the bottom of the disk cases were so well sealed by the rubber surrounds. We had backups of course but the disks were a write-off. I still have the platters from them in my garage.

I've been distracted from the project by something else totally bizarre that has happened in connection with it over the last five years. It seems that somehow my brain got confused about my plans to build a computer from the past many years later and built inside my head a computer that, to put it simply, processed data from the future in the past. It even used a feature of my demonstration Easycoder programme to do it. I suppose if it is possible to emulate an H200 on a PC then it is possible to emulate a quantum computer in one's mind, even if that seems ridiculous. It's taken me five years to work out why I abandoned my work on the H200 to write a science fiction novel and apparently that's the answer. I don't understand quantum computing but apparently the output can appear before the input has been fed in if I'm right. That's all a bit like Hitchhiker's Guide to the Galaxy, knowing the answer but having no idea what the question was. Anyway, I've now set out the whole story on my new website www.menstemporum.uk (http://www.menstemporum.uk/) so that I can get on with my slightly more conventional life. If you visit it you'll see just how much the H200 project was tangled up in it. It's all pretty paranormal though and even I'm unsure what it was about. Apparently my mind is just as capable of spending time in the future as in the past.

1944GPW
February 9th, 2016, 02:14 PM
... apparently the output can appear before the input has been fed in if I'm right. That's all a bit like Hitchhiker's Guide to the Galaxy, knowing the answer but having no idea what the question was.

Sounds a little like Asimov's famous classic short story 'The Endochronic properties of resublimated Thiotimoline' in which he describes a chemical substance that dissolves before the water is added, written in the form of a pseudo-scientific research paper.
There was a followup story 'Thiotimoline to the Stars' in which it was used for a spaceship warp drive. Great stories from an SF master, read them both many years ago now.

Steve.

durgadas
May 27th, 2016, 11:23 AM
Hi Rob,

I have had a lingering interest in building a virtual H2040, having had some experience with that in the mid 70's. Before I embark on such a project, I wanted to know what sorts of software there might be. I'm not sure of the relationship between the 200 and 2000 series, although I know they are very close. I was hoping there might be something like OS/2000 out there, but almost any software might make it worthwhile. Even with some documentation on the OS/monitor I might be able to emulate it.

durgadas
June 13th, 2016, 04:53 AM
Hi All,

I have modeled (most of) a 2000-series machine core and have tested most of the instructions (only one peripheral so far, the Line Printer in a crude form). From what I read in the documentation, the series 2000 should be completely upward compatible - although I suspect some things like OS or Monitor might not tolerate the differences.

I am now trying to run the Pi-calculation program MACHIN and running into difficulty. It is crashing due to what appears to be a missing word-mark, the affected LCA instruction ends up overwriting the program. It is taking some time to get my head into the programming style, especially since I spent the last 30 years UN-learning self-modifying programs! One of the things I'm wondering is if this program was ever run on real hardware - I gather it may have been written in modern times and thus did not originate from an original HW200 program.

Also, are there any other HW200/2000 programs out there? Ideally, in electronic form (I was able to extract code from the PDF Easycoder listing, for example). But anything that might help verify/debug the virtual machine would help.

Also, any pictures and documentation on the front panel and console would be nice, for when I start to build the GUI.

durgadas
June 15th, 2016, 06:06 PM
I was able to fix enough bugs to get MACHIN to run, so now it's on to other testing. Working on a simple assembler, unless there is a copy/listing of Easycoder out there.

durgadas
June 20th, 2016, 04:31 AM
I've made a fair amount of progress, using a simple/crude Easycoder mimic. I've even been testing the virtual H2000 interrupt and relocate/protect mechanisms and have a simple monitor program to launch other programs in protected/relocated mode (and process their violation interrupts). Of course, both the virtual H2000 and my assembler code are based on my (flawed) understanding/interpretation of the "Models 2040 Through 2070 Programmers' Reference Manual", which is very complete but still leaves some questions and requires multiple passes in order to collect the key bits of info on a given subject. I can't confirm if this is an accurate virtualization.

So, any code out there that I can look at would help fill in blanks. MACHIN was very helpful but does not use a broad set of instructions or features.

durgadas
June 23rd, 2016, 05:47 PM
Not sure if anyone is out there, but have made some progress and even implemented a GUI front-panel. Not 100% functional yet, but getting close. Here is a short video of it running MACHIN. https://youtu.be/fphxmBdgQLM The real-time display of address/data really slows it down, even if it is limited to just SR and op-code (as shown here).

durgadas
June 30th, 2016, 02:19 PM
I have setup a project page for my effort. http://honeywell2000.durgadas.com/ There is a download page linked from there where you can get the "jar" file for the virtual H2000. I'm still hoping to find folks that can help, with either more details on how the machines operated or with code to run.

RobS
November 15th, 2016, 01:14 AM
Hi durgadas,

My sincere apologies for not responding earlier but I haven't been getting notifications of new posts on the thread for some reason. Ah, you just can't trust these computer thingies can you?

I am truly impressed by what you have done. That is a lot of work. As I mentioned on my website I had contemplated designing a visual emulation of the control panel but decided that some direct graphics software would be needed to work fast enough. I looked at the possibility of using DirectFB under Linux, but my work on the actual hardware has to take precedence. As the pictures on my website are generated from text files using PovRay I have all the measurements of the control panel shown there, although the real thing may be slightly different. I'll find out when I finally get it from California. When I can find the time I'll see whether my graphics can be incorporated into your programme as I spent a long time making them as realistic as possible.

MACHIN was written to run in ADMODE 2 but there is no CAM instruction in it as it was intended to be run on a minimum configuration machine which would always be in ADMODE 2 anyway. I can't remember what the initial ADMODE was on the larger machines. Regarding the assembler, I did once have a listing of the Easycoder A assembler source code but it looks like it got thrown away at some time, which I deeply regret now.

After working in Easycoder on a small machine in the 1960s I moved on to using COBOL on the bigger machines in the 1970s, so my knowledge of them at machine level is by no means so detailed. I am happy to try working out any of the problems with you though. I'll also check my previous contacts with former H200 series users who might be interested. Most people just can't remember much of the details now though.

It's my wife's birthday today, so I have pressing commitments now, but I just wanted to reassure you that I am still around and my project is crawling along. It gets boring if I just keep reporting my lack of progress on the thread, which is why I haven't posted anything for a while, but I'm hoping to get back to work on it soon. I'll get back to you. Keep up the brilliant work.

Regards,
Rob

durgadas311
June 15th, 2017, 10:13 AM
A little off-topic.
"Aroma Therapy" - I had the chance to walk the hallowed halls of an old IBM facility recently, and as I ducked into a stairwell, was overcome with nostalgia... the source was a distinct smell from my past...

The gentle blending of
cigarette smoke, machine oil, and punch-card chad,
slow-cooked on an electric motor,
infused into linoleum.

It survived fifty years in the linoleum of that stairwell... ah, the good old days...

Gitmoray
August 23rd, 2017, 12:29 PM
Just found this after losing track of it for the last couple of years, but alas, apparently RobS is no longer contributing ?

I was a Field Engineer with Honeywell I.S. back in the 70's in Los Angeles. trained originally in the 400/1400 line of second generation computers, and was privileged to help do preventive maintenance one afternoon on an old D-1000 vacuum tube computer before it was finally decommissioned.

During five years at Honeywell I worked on H 115 and 125, H200, 1200 and 2200, but spent my major time working an a dual H4200 site (Blue Cross Blue Shield of Socal). from 1974 to mid 1975 I worked all over, but spent major time at a dual H2070 site in El Segundo (Kaiser Permanente). I have looked around for pics of the H2070, and once found a guy in Australia who sent me some, but they have somehow disappeared from my files. If anyone still has some, please send me a pointer.

Hope all is well with RobS...very cool project he has undertaken.

RobS
October 25th, 2017, 06:28 AM
Oh, I'm so sorry Gitmoray, but my notifications weren't set up correctly and I don't visit this site regularly, so didn't see your post. If you have any recollections of the H115 and H125 then they could well be of use to me as the technology that I have uses integrated circuits that I suspect were used in some of these machines whereas the earlier H200 used transistors. Hence I suspect that my machine will be closer to an H125 than an H200 in fact.

Hopefully I have now fixed my notifications so that I get emails when someone posts. The irony is that I have now accepted a position as a voluntary staff member on another site, not connected with computing, that also uses vBulletin, so I am more conversant with the system these days than I was when I joined this site. By coincidence that other site had a fault that resulted in my not getting email notifications when many other members were and it took some effort on my part to prove that the administration of the site was the problem. In this case here though I suspect that the problem was down to my negligence.

Progress on my project has been very slow as I have had something else to cope with this year. I did find the time to install a couple of cheap switch mode PSUs in my workshop to boost the 28volt power lines a while back but haven't got back to testing the memory unit since then. I also wrote a programme for the Arduino MEGA 2560 board that will act as a test interface between the H200 memory unit and my PC so that I can run memory tests using programmes on the PC. Fortunately the H200 memory unit has its own internal timing circuits, so can run asynchronously rather than needing a synchronising master clock for data transfer. The MEGA 2560 board has many interface pins and a good few of them are needed for the parallel connections to the H200 memory, so I still have the task of constructing the custom plug-in cable to connect the two.

I can't recollect whether I have mentioned it before but my other preoccupation is strangely connected with my H200 project. In 2010 I first conceived the idea of building the machine but didn't have the right core memory modules, so I shelved the project hoping that I might find the right memories in the future. Apparently somewhere at the back of my mind my subconscious misconstrued my desire to "find the right memories in the future" and early in 2011 literally provided me with my own memories from my actual future, which I unwittingly used to write a science fiction novel about people being able to acquire information about future events. In particular the story in it mentioned two minds connected across six years in time and, as it is now six years since I wrote the novel, I have been preoccupied with the events that have happened this year and evidently inspired what I wrote back in 2011. I don't ask you to believe me about this but I have certainly had to cope with it myself. Just one simple example will demonstrate what I am up against.

On Monday the 13th of June 2011 I sent an extract from my unfinished novel to a literary service for assessment and they gave me their comments. Shortly after that I added the chapters that mentioned the six year period spanning events. In March 2017 I became concerned that something bad, maybe even fatal, connected with my novel would happen in the coming months and I wondered whether it would affect myself or someone close to me. In fact on Monday 12th June 2017, within 24 hours of precisely six years after my contacting that literary service, I received from them a circulated email reporting the death of their much loved founder and director in April after a short illness. I didn't know the lady, but was both shocked and saddened by the news. The moral is apparently to be careful what you wish for as some playful spirit may choose to misinterpret your intentions entirely.

In order to put my experiences into context I joined the British Society for Psychical Research, the members of which do stringent experiments to determine the truth about "psi". Just a few days ago I attended a talk given there by Ed May, who was the director of the American military Stargate Project for most of its existence. This project was given something like twenty million dollars to use psychics as "remote viewing" spies during the cold war, probably the largest outlay on psychical experimentation ever made.

With stuff like this going on in my life perhaps you can appreciate why my H200 project has been collecting dust. Strangely though, this year my experiences have been so convincing for me that I am inclined just to accept them as normal. Far from feeling in any way special I assume that we all have a certain amount of psychic ability within us but we are inclined just to either take our "intuition" for granted or else ignore the hints from the future that our minds are maybe continually giving us. So, torn between writing an entire book on my experiences and just putting them to one side, I am presently inclined to do the latter and get back to Honey Pi. However, I am still dithering between indulging in the nostalgia of the past and the intriguing possibilities of the future, so watch this space for clues as to my decision.

macieksoft
November 1st, 2017, 10:45 AM
@Durgadas emulator seems to be nice. Hoewver i know nothing about this machine :-(
Are there any sites where i could learn some basic things to start with? I mean especially such simple things like entering instructions trough the front end panel (if it is even possible) and so on. Then the list of instructions with explaination on all of them would be nice. Just some things that could let me start with Honeywell.
If somebody could just tell me a simple step by step guide to enter a single instruction into memory so i would have a point to start with :-)

The IBM keypunch simulator included with it seems to be one of the coolest ideas i seen. It is in fact my reason why i'd like to learn on how to get virtual Honeywell runnung. Just to have some fun with those virtual punched cards procesing :-)

And will there be some telnet terminal connection option included to emulate TTY connection? I am not even sure if Honeywell was able to connect to the standard TTY but i guess it was as all other mainframes seems to have option to connect to the terminal trough TTY. I know there is a build in line printer but i am asking about remote TTY trough telnet.

And are there any chances for model 129 keypunch? AFAIK it was most advanced one with 6 programs stored in electronic memory instead of program durm. You could also make the card in reading station visible, this would require larger resolution screen to show both cards, but it could be optional so users with larger screen could see both cards.

legalize
November 2nd, 2017, 01:42 PM
@Durgadas emulator seems to be nice. Hoewver i know nothing about this machine :-(
Are there any sites where i could learn some basic things to start with? I mean especially such simple things like entering instructions trough the front end panel (if it is even possible) and so on. Then the list of instructions with explaination on all of them would be nice. Just some things that could let me start with Honeywell.
If somebody could just tell me a simple step by step guide to enter a single instruction into memory so i would have a point to start with :-)

I think this is the right bitsavers directory containing docs for this machine:

http://bitsavers.trailing-edge.com/pdf/honeywell/series200/

durgadas311
November 7th, 2017, 02:10 PM
I've gotten a lot of information from bitsavers. The "Honeywell Programmers Reference Manual" is probably the best start. My emulator has a built-in assembler emulation, but you can also enter programs into memory via the front panel - if you have the patience.

I've almost-exclusively programmed in "register architecture" assembly language (8080/Z80, etc), so the 200/2000 was quite different. Some things I had to learn: The assembler assigns an address to a symbol based on context. Instructions use the "leftmost" character address (first character) while data use the rightmost (last character) address. Data fields are terminated by word marks, and if you forget to ensure a wordmark exists, bad things happen. Also, the subroutine call/return semantics are a bit strange. The branch instructions save the next instruction address in BAR ("B" Address Register) and thus work as either a branch or "branch and link" (or CALL) depending on your code. The subroutine then must save the BAR and branch back to that address in order to "return". Also, if you use an offset to a symbol (e.g. SYMBOL+3) you may need to take into account the current running address length of the processor - which can be 2, 3, or 4 characters. So, a typical subroutine framework for running in 3-char address mode would be:


SUBR SCR RETN+3,70 SAVE BAR IN RETURN LOC
...subroutine code...
RETN B 0 RETURN - ADDR REPLACED WHEN CALLED

There are other ways to accomplish subroutines as well, but this is a good starting example. Passing parameters to subroutines is a whole 'nother subject... and if you want to support recursion, well...

I put some basic instructions for operating the system here: http://honeywell2000.durgadas.com/h2000operation.html, which includes a link to a page on the front panel. Hopefully that will get you started. There are also some instructions in Honeywell manuals, but I've not found a single source for all front panel operations. They seem to have certain operations embedded in various documents. Like some information on bootstrapping in certain MOD1 documents, or the hardware maintenance manuals, and basically places where certain procedures were required. My understanding of machine operation is based on bits and pieces pulled from many different manuals. Unfortunately, I never got to operate the real hardware, I just watched.

Anyway, I'm sure you'll have fun... let me know if you have questions.

RobS
November 8th, 2017, 12:40 AM
Thanks for that explanation Durgadas. As a past H200 programmer I would probably get in too deep to the different style of working necessary on this type of machine, but I'll do it anyway.

Unlike register machines the great advantage of a two address character machine is that fields can be any length. If you want to do maths to hundreds of significant digits then you just make the fields that big, but the instructions are just the same because they process whole fields no matter how large they are. That is why the word marks are so important, because the processing of a single instruction doesn't stop in the right place if one is missing. It is true that the basic instructions reference the right hand end of fields, i.e. words, but the advanced instructions include the Extended Move instruction that can process from left to right or right to left and terminate on a word mark, item mark or record mark. Hence it is possible to construct and process a four level data structure containing characters, words, items and records entirely within the hardware without any software iteration being necessary. I will have my work cut out just building the hardware for the basic instruction set though.

That method for writing subroutines illustrates one important point about the simplest programming techniques, that the machine code can be self-modifying. Register machines tend to hold all variable working data in the stack or data segments and the executable portion of a programme does not change, following the Harvard architectural model, but with the Von Neumann architectural model the code is also regarded as data and therefore can change itself while running. This may be regarded as bad practice by modern control freaks but is actually extremely versatile and the key to how it was possible to write tiny programmes such as my Pi Factory (http://honeypi.org.uk/bigimage/MACHIN.PDF) demonstration programme. There is so much self-modification there that it is very difficult to work out what is happening without the assistance of the clues given in the comments and my notes.

Modern programmers seem to consider the "Go To" instruction to be the work of the devil and bound to result in chaos, but here it is necessary and normal to modify GoTo instructions while the programme is running. Oh horrors! How could any programme possibly run reliably using code like that? The truth is that nowadays programmers only write the easy high level code as the more critical low level code with its naughty but essential GoTo's has already been built by more experienced system programmers. In fact nowadays that low level code is microcoded into the central processor's hardware during design. In the case of the H200 almost all the register handling was similarly hard coded, so the programmer didn't seem to need to think about it because the data was put back into main memory by the hardware automatically.

Although the programmer didn't have to use data registers directly they needed to understand what the machine was doing with address registers behind the scenes in order to return from subroutines and take full advantage of instruction chaining. This latter technique involved leaving the addresses out of instructions because the right ones were already in the registers following execution of the previous instructions. You have to understand instruction chaining to be able to comprehend what the assembled code in a typical programme is actually achieving. The H200 programmer's reference manual explains how each instruction uses and alters address registers so that a programmer can use this important feature effectively.

Another programming trick was making instructions temporarily disappear from the code. This usually involved placing a NOP (No Operation) immediately before the instruction during assembly. To disable the instruction, code elsewhere removed the word mark from its first character. As a result the NOP treated the instruction as its own parameters, which it always ignored, and passed control to the next instruction along. The hidden instruction could be reinstated simply by putting the word mark back on it. This technique allowed any instruction to be switched on and off as required. There are examples of it in my Pi Factory programme. Such techniques required very clear thinking on the part of the programmer to be reliable. This is where the idea of a programme being a "finite state machine" rather than a predefined procedure is essential to grasp. At all times the whole programme had to be in a valid meaningful state.

The style of programming used on these old character machines was very much aimed at minimising the memory space and machine cycles used because memories were small and expensive and the processors were slow by modern standards. Nowadays memory is dirt cheap and processors incredibly fast, so the code doesn't have to be so efficient and it can be designed to permit rapid reliable programming by relatively inexperienced programmers. My Pi Factory programme is tiny, but it took me two solid weeks of intense decision making to make it work to my very demanding specification. I also subscribe to an online writer's forum and am in fact now a staff member there, which explains why I don't post here very often. We discuss how much thought can go into a very effective piece of writing and how people can spend so much time reading, analysing and discussing famous works such as those of Shakespeare and much-loved poems by the great poets. However, back in the early days of computing just as much thought had to go into writing code that would fulfil the requirements. A clever piece of code that speeded up a long process could result in the computer operators going home an hour or two earlier at the end of each evening shift. In those days that was like poetry to all concerned.

durgadas311
November 8th, 2017, 07:40 AM
I did some work on punch card data processing equipment, although not the 129 Keypunch machine. You can see that here: http://sims.durgadas.com/punchcards/ibm029.html

Chuck(G)
November 8th, 2017, 08:16 AM
Very similar to the IBM 1620 and 1401, but in particular, the 1620.

Fields and records, addressed respectively, from the low-order position and from the high-order position.

On the 1620, there's no way to directly (or indirectly) read the P-counter, though, I suppose, it's possible to guess it by modifying instructions. The calling sequence generally looked like.

Exit: Branch (filled in by caller)
Entry:
...
Branch to Exit

The 1620 did have a "hidden" register that would save the location of the next instruction before a "branch and transmit" instruction was executed, but said register was operated on only by the "branch back" instruction, which made the facility useful only for a single nesting level.

The subroutine calling method was shared by quite a number of machines, including the CDC 6000-7000 supercomputers. ("Return jump" instruction). PDP-8 certainly uses that as well.

ClausB
November 14th, 2017, 08:30 AM
I have setup a project page for my effort. http://honeywell2000.durgadas.com/ There is a download page linked from there where you can get the "jar" file for the virtual H2000. I'm still hoping to find folks that can help, with either more details on how the machines operated or with code to run.

Cool! I'll be trying your emulators.

Looks like the FORTRAN manual you posted (http://sebhc.durgadas.com/hw2000/docs/H200-027_Fortran_Compiler_D.pdf) is the next edition of the one I mentioned upthread. I have not scanned mine yet.

durgadas311
November 15th, 2017, 03:17 AM
I should note, that the FORTRAN manual is just a redistribution from bitsavers - for convenience sake. Not a personal collection or otherwise unavailable document. Same goes for nearly all documents I post.

Also, a disclaimer about my FORTRAN and EasyCoder emulations. Neither is a complete implementation of the respective language. I implemented enough to (hopefully) make them useful. Plus, some features require more information, that I don't yet have.

ClausB
November 16th, 2017, 01:29 PM
Pardon my Java noobness, but when I try to run CardPunch.jar, I get the error: "Could not find the main class. Program will exit." My JRE is version 6, which came with the Arduino IDE. Am I doing it wrong?

durgadas311
November 16th, 2017, 05:47 PM
I'm pretty sure the problem is Java version. I compiled on Java 8, but used backward-compatibility options for Java 7. Java 6 is very old. The error message is odd, and not very helpful, but I would not expect that JAR to run on Java 6. Can you get Java 7 or 8?

RobS
November 18th, 2017, 08:35 AM
I have just received a scanned copy of the H200 Main Memory Setup Manual from a contact in Switzerland. This is a very useful document for me as it isn't just a field engineer's guide but the full 49 page instruction manual for setting up the memory when it is first built. Hence it's exactly what I need to ensure that I adjust the unit for optimum reliability ... if it works at all of course. That's yet to be discovered. Some of the driver boards definitely aren't working correctly at present, so it may be a while before I know.

42012

RobS
January 2nd, 2018, 11:48 PM
I have now installed an Arduino Mega 2560 board as a temporary USB interface between the memory unit buses and a PC, so yesterday I was able to run dynamic tests on every memory location in the two magnetic core stacks to verify that they are fully functional, which they are. These stacks were salvaged from a scrap heap decades ago and were just static mementos until now. Knowing that they are in full working order is an incentive for me to get on with the project work this year. There is much more to do before I can actually store data in the memory unit but this is a positive step forward and good news.

Before I ran the read-write tests I dumped the existing contents of the memories. Magnetic core memories retain data persistently, so there was still data present from the last time that the computer that originally contained them was used decades ago. Although the data was still readable it wasn't possible to extract any meaningful information from it. In fact it was so ingrained into the magnetic cores that it took several read-write cycles to erase it entirely. For a while I thought that the stacks were faulty, but they just needed some exercise after being inactive for so long. At my age I know how they feel sometimes, especially just after the Christmas holiday.

A Happy New Year to all at VCF.
Rob

RobS
March 8th, 2018, 05:45 AM
I have now completed construction of the main memory unit. During testing one of the two core memory stacks produced some erratic results, but my colleague Marcel has others in his collection and will give them to me to try out the next time that we meet up. Apart from any minor problems that might need fixing I consider this phase of the project to be finished. However, the unit will need fine tuning for optimum reliability, but that is best done when the final operating environment is in place, e.g. a proper cooling system and power supplies set at the standard voltages.

Even though the memory unit has a digital interface it is fundamentally analogue technology. It has fifty-two Helitrim potentiometers which set the important voltages, currents and timings and also some components can be replaced to adjust other key factors such as pulse rise times. I now have a copy of the official fifty page set-up instruction manual for the unit, kindly sent to me by a contact in Switzerland, so I know what has to be done when the time comes. Hence the unit is hardly plug and play and no doubt I will spend some time making final adjustments to it.

I am now moving on to design of the control memory and other registers. For this I will use the 1960's Honeywell ICs in my collection instead of the original high speed magnetic core memory stack. I do have one of those but don't have the circuit boards needed to operate it or their schematics and don't relish the idea of designing my own. That device was a differential magnetic memory running at four times the normal speed for a core memory, so the circuitry was critical and it was always the most likely component to fail as well as being the only relatively advanced technology in the Honeywell 200. As the machine was aimed at the bottom of the market most of its technology was relatively simple but inclusion of the high speed control memory was what gave it its outstanding operating speed. By using a stack of flip-flop ICs instead I will have a far more reliable device that can easily be designed to run at the same speed without breaking the constraint of using only 1960's Honeywell 200 technology in my design.

I have dismantled the main memory unit now in order to add the sockets to the other half of the same backplane where the control memory will be located, so it is currently just a pile of circuit boards and a lot of wiring on the backplane.

The project is now getting more interesting as, rather than just getting Honeywell's original circuit boards to work together as they intended, I am now designing my own solutions to the problems that they faced, albeit using only the small scale integrated circuits that they had back then with just two logic gates per chip. The functional modules of the machine will follow their original design as much as possible, but the internal design of each module will be my own. In particular, the timings of all the internal operations will be the same as in the original machine so that it will perform in exactly the same way as that did. I have to suppress the urge to build a better machine than the H200, but just building the equivalent is likely to be enough of a challenge.

RobS
March 9th, 2018, 05:52 AM
The links and contact page on my website was entirely out of date, so I have now updated it including the links to this site and thread. That page also now contains my email address for use by anyone who prefers to contact me directly about the project. I have also added a link to the article that I wrote about the project for the Computer Conservation Society here in the UK back in 2014. You may have to refresh the page in your browser to get the up to date version.

At present this thread still remains the sole place where I am reporting progress on the project as I haven't organised my own website to do this yet. Once I have done that I will start posting photographs there.

durgadas311
March 14th, 2018, 05:14 AM
Great to see this progress! I'll bet you can almost hear the system running now!

Do you think it will be ready for a cameo spot in the remake of "Billion Dollar Brain"? ;-)

RobS
March 14th, 2018, 06:44 AM
I can hear it running already actually, but that's just the fans cooling the vintage PSU's.

The problem with "Billion Dollar Brain" is that the key scene portrays cards being read into a model 223 card reader. Okay, so maybe building a 223 from scratch may be within someone's capabilities, but finding a supply of punched cards could prove more difficult. Anyway, there seems to be a misconception that the H200 was the billion dollar brain in the title, but it clearly wasn't. Apart from being a free-standing small mainframe in its own right the H200 was also used as a satellite machine for far larger ones, which is why it was designed with such versatile peripheral capabilities. The scenes in that film evidently portray such a set-up.

At least in that film the H200 shown was a real complete machine actually being operated normally. H200 control panels were very photogenic and therefore appeared in other films where there was no evidence of there actually being an H200 computer as well. In the title sequences of that film they did put a lot of bogus stickers on the control panel and even when the real machine was shown it had a prominent HONEYWELL sticker on the control panel where there shouldn't have been one to provide a little extra point of action product placement.

I'm currently putting together a test circuit to determine the precise operating characteristics of the Honeywell flip-flop ICs that I will be using in the control memory so that I can design the PCBs for it. Sixteen identical PCBs with gold-plated edge connectors will cost a fair bit for my supplier to manufacture, so I need to get the design right. I know the basic logic functions of the ICs but also need to assess the fan-out and line driving capabilities as well as the effect of the feedback capacitors that Honeywell included in their designs. I noticed that in older designs they were included but in later versions of the same boards some were omitted, so there seems to have been some lack of clarity about when they were really needed. Modern digital ICs don't have analogue feedback pins to permit wave-shaping adjustments, so design with them is much simpler, but these ICs were used in circuits on wire-wrapped backplanes with long interconnecting wires and plenty of scope for induced noise.

So far I have discovered that with an 18MHz clock pulse into a flip-flop switching at 9MHz a 33pf feedback capacitor changes the (sort of) square output pulse into a triangular one because the rise and fall times are slowed down so much. Interesting. No doubt at slower switching speeds that might be useful. I can see why the standard logic boards were described as containing "slow gated buffer amplifiers". Oh well, I'd better get back to the workbench to add the next frequency divider stage. The basic cycle clock rate of the H200 was 4MHz, so I should be using a 16MHz crystal anyway but don't have one handy, not that it matters for now.

durgadas311
March 14th, 2018, 07:02 AM
The problem with "Billion Dollar Brain" is that the key scene portrays cards being read into a model 223 card reader. Okay, so maybe building a 223 from scratch may be within someone's capabilities, but finding a supply of punched cards could prove more difficult. Anyway, there seems to be a misconception that the H200 was the billion dollar brain in the title, but it clearly wasn't. Apart from being a free-standing small mainframe in its own right the H200 was also used as a satellite machine for far larger ones, which is why it was designed with such versatile peripheral capabilities. The scenes in that film evidently portray such a set-up.


Yeah, I got that impression watching the scene with Karl Malden. From what I could follow, he was doing little more than printing out a message from a mag tape, possibly after decrypting it - which was probably all local to the H200... not that there was actually a "billion dollar brain" attached to the H200...

RobS
March 14th, 2018, 07:41 AM
Yeah, I got that impression watching the scene with Karl Malden. From what I could follow, he was doing little more than printing out a message from a mag tape, possibly after decrypting it - which was probably all local to the H200... not that there was actually a "billion dollar brain" attached to the H200...

No, I doubt that there was. The film was made with the cooperation of Honeywell and that set was quite possibly a Honeywell data centre with many computers in it.

I've now added the next flip-flop to halve the frequency again, so I'm now getting nine pulses in two microseconds. It should be eight if I use the correct crystal, but who's counting? Oh yes, I am. I must add a 16MHz crystal to my shopping list. Two microseconds was the cycle time of the main memory and there were eight distinct time slots within each such cycle. Control memory cycled four times faster, so executed a read-write cycle every half microsecond, which is my design target. The logic gates appear to have around a 25 nanosecond propagation delay, so with just 250 nanoseconds per time slot I have to bear that in mind. Those feedback capacitors really slow response times down though. Perhaps I don't need to provide for them in my PCB design at all.

durgadas311
March 14th, 2018, 07:46 AM
I'm currently putting together a test circuit to determine the precise operating characteristics of the Honeywell flip-flop ICs that I will be using in the control memory so that I can design the PCBs for it. Sixteen identical PCBs with gold-plated edge connectors will cost a fair bit for my supplier to manufacture, so I need to get the design right. I know the basic logic functions of the ICs but also need to assess the fan-out and line driving capabilities as well as the effect of the feedback capacitors that Honeywell included in their designs. I noticed that in older designs they were included but in later versions of the same boards some were omitted, so there seems to have been some lack of clarity about when they were really needed. Modern digital ICs don't have analogue feedback pins to permit wave-shaping adjustments, so design with them is much simpler, but these ICs were used in circuits on wire-wrapped backplanes with long interconnecting wires and plenty of scope for induced noise.


I'm guessing the parts are RTL/DTL ICs then? I never worked with that technology, but saw some in the Wang 600/700 programmable calculators. I didn't realize you could still get those parts, or is this recycled chips? Anyway, kudos to having the courage to work in that space! I saw some wire-wrap backplanes (newer tech) that used twisted-pair wiring... did Honeywell use any of that to reduce noise?

RobS
March 14th, 2018, 08:36 AM
I'm guessing the parts are RTL/DTL ICs then? I never worked with that technology, but saw some in the Wang 600/700 programmable calculators. I didn't realize you could still get those parts, or is this recycled chips? Anyway, kudos to having the courage to work in that space! I saw some wire-wrap backplanes (newer tech) that used twisted-pair wiring... did Honeywell use any of that to reduce noise?

I am using original ICs manufactured around 1971 althought the designs for many of the boards that they are on date from 1969 or earlier, so they were certainly in use in the 1960s. The original transistorised H200 used discrete diode and transistor logic, as is evident from the schematics. The earlier circuits had single ended outputs with pull-up resistors but the later circuits used push-pull transistor output stages. From my tests on the ICs they also appear to have push-pull output stages. I think that they are more advanced than RTL (I have some old RTL ICs which are much more primitive.) but I have no reason to believe that they are TTL, so DTL is the most likely. I suspect that they are basically integrated circuit equivalents of the technology used in the previous discrete diode transistor boards. Those had feedback capacitors and Honeywell appear to have included them in their DTL design as well as external components, all the rest being within the ICs. The flip-flops are relatively sophisticated, being master-slave devices with three pairs of anded input gates and a "recirculate" pin which causes the current state to stay latched during clock pulses although the inputs can still set the flip-flop. This style of flip-flop logic may be the reason why on the H200 control panel you could turn individual bits on but could only turn them off by clearing an entire display line. Hitting the "Clear" button on the left hand side presumably killed the recirculation of the data in the flip-flops. One might assume that the buttons worked in press-on-press-off fashion, but the majority of them didn't. The H200 was designed to be as cheap and easy to build as possible, for which I am grateful.

The boards in my collection from the 1970's contain in total around 5000 ICs, which should be enough to build the machine. There are only seven main types of IC on them, so I have about a thousand of each of the common types. They each contain two logic gated buffers or one flip-flop, so I actually have around 9000 to 10,000 gated buffers to play with. If I really get short I may be able to add extra diodes to extend the fan-in of some of the gates. I can also add transistors as output boosters to increase fan-out where necessary. I am likely to spend as much time experimenting with the ICs as actually building the machine, but it's all part of the fun for me.

My test circuit is still sitting here clocking up cycles while I'm typing, so I ought to get back to it. My oscilloscope must be getting bored with tracing it by now.

RobS
March 14th, 2019, 10:40 AM
Gosh, it's now a year since I last posted to this thread. I'm so busy working on this project that I haven't even found the time to update my website for it either, but rest assured that I am making significant progress daily at present and the enterprise is in good health. I'll try to give more details but don't have time today now, having just written a lengthy post about wire-wrapping in another thread.

I'll be back.

daver2
March 14th, 2019, 10:51 AM
On a project I am currently working on - we have some wire-wrap configuration posts on one of the cards we are remanufacturing. The PCB assembly firm had to train some operators to perform the wire wrapping...

NASA have a very good article on their wire wrapping Standards and Expectations. They describe the 'brick wall method' that Rob describes as a requirement such that future work/modifications can be accommodated. They also recommend leaving one spare set of turns available on each wire wrap post for future modifications. it's a good read...

Dave

durgadas311
March 14th, 2019, 11:10 AM
Gosh, it's now a year since I last posted to this thread. I'm so busy working on this project that I haven't even found the time to update my website for it either, but rest assured that I am making significant progress daily at present and the enterprise is in good health. I'll try to give more details but don't have time today now, having just written a lengthy post about wire-wrapping in another thread.

I'll be back.

Great news! I've been wondering if the project was advancing.

Probably not of use to you, but I've been working on a "C" cross-compiler for the H200/2000, and have GUN/Unix style assembler/linker working. It is a bit of a odd fit, since the H200 architecture is so foreign to common Unix architectures, but it's already got me making progress on reconstructing some sort of OS for the H200/2000. Of course, if you've only got 2K RAM then there's not much use for an OS. I think you've already got a cross-assembler anyway.

billdeg
March 14th, 2019, 11:11 AM
thanks for the update.

ClausB
March 14th, 2019, 11:32 AM
Looking forward to hearing of your progress.

RobS
March 15th, 2019, 01:21 AM
Back as promised. However, I am having serious trouble with this website and have just irretrievably lost the substantial post that I typed, so will now go away and fume before coming back to try again some other time. Even the autosave facility didn't save my text, so next time I will have to treat this as a hostile system, type my text in a separate editor and then paste it here in one go, although I know that vBulletin is notorious for screwing up pasted text as well. I regularly, almost daily, subscribe to another vBulletin site and don't get these problems, so it isn't likely to be a problem at my end.

Sorry, but I don't need this hassle when I have such a lot of work to do on my project.

durgadas311
March 16th, 2019, 08:37 AM
I share your frustration. Nothing worse than composing "the perfect" post and then losing it. Maybe posting to your honeypi site first might be good anyway, as we can all read it there, too.

commodorejohn
March 16th, 2019, 10:03 AM
Even the autosave facility didn't save my text, so next time I will have to treat this as a hostile system, type my text in a separate editor and then paste it here in one go, although I know that vBulletin is notorious for screwing up pasted text as well.
I highly recommend turning off the fancy formatting editor and just using plain text with BBcode directly. It makes things a hundred times less error-prone, and less balky to boot.

Chuck(G)
March 16th, 2019, 10:16 AM
Fancy formatting editor? I've been here how long and I don't even know about that? :shock:

commodorejohn
March 16th, 2019, 11:15 AM
It only appears if you have Javascript enabled, so some of us NoScript junkies may never have seen it :lol: I appreciate the intent, but I've never used a rich-text editor on a web forum that wasn't so janky as to not be worth the trouble...

RobS
March 17th, 2019, 03:37 AM
I highly recommend turning off the fancy formatting editor and just using plain text with BBcode directly. It makes things a hundred times less error-prone, and less balky to boot.

I don't think the problem is the editor itself but the fact that the site seems to think that I'm inactive while I'm typing on it, so logs me out. I can overcome the problem by requesting a preview every few minutes as that wakes the site up to the fact that I'm still active on it. I regularly subscribe to an online writers' forum that uses vBulletin and that doesn't have a login timeout because we do actually pause to think about what we're writing there, otherwise we're likely to get flack for being inept. Here the expectation seems to be that one will bang something in quickly and then post it without any further thought, hardly appropriate for such a technical subject to my mind.

Well, I'd better get off the site now to type my real post elsewhere. I'll be back.

daver2
March 17th, 2019, 03:52 AM
Hi Rob,

Yes, I have learnt the hard way a few times that for a long or complex post you are better off editing your post outside of VCFED then doing a copy/paste/correction within VCFED itself.

My initial problems occurred when I was using VCFED at work during lunch break (i.e. nothing to do with vBulletin but the bandwidth usage out our end). That would definitely cause me to loose the post text. So, I would always play it safe and do a 'copy' before hitting the 'post' button anyhow...

Dave

RobS
March 17th, 2019, 04:16 AM
Maybe it's a problem specific to the UK on this site then Dave. That's ironic given that we're just celebrating the thirtieth anniversary of the conception of the World Wide Web, as opposed to the older Internet, by a Brit. It's also ironic that we're still using legacy bulletin board software and code instead of HTML/XML for sites like this, but that's lack of progress for you.

RobS
March 17th, 2019, 04:55 AM
Okay, hereís a quick progress report as I need to get ready for our Sunday lunch soon. (Waistcoat and tie of course, full English roast with wine, candelabra and linen napkins, even a tablecloth! Itís the full works every Sunday here. What my angel wife will wear will be a pleasant surprise as usual as well. We like to keep Sunday special.)

The 8k magnetic core memory unit is working with just the fine adjustments to do and maybe I will replace one of the 4k core memory modules that was glitching a bit. Iíve removed all the logic modules for the unit from the backplane now to do work on the backplane and wonít reassemble the unit until I have at least a rudimentary CPU to run it. The memory has fifty-two trimming potentiometers to tweak and a thirty page instruction manual on how to do that, so that task can wait for now. The unit is connected to the CPU logic by plug-in patch boards, so I could devise a modern RAM based substitute to use while testing the CPU logic to avoid any core memory errors confusing that testing.

I have assembled a quarter of my 240 bit control memory, so thatís sixty flip-flop ICs, and that provides the four essential fifteen bit address registers, which are the sequence register, A and B address registers and a work register. These are adequate for execution of the majority of the basic instructions, the other twelve registers being used for I/O and optional features that I can add later. I am currently designing and building the input and output registers for the control memory and then will have to put together some logic to test the design once Iíve wire-wrapped sufficient connections on the backplane. The input register also incorporates the essential fifteen bit address fast increment/decrement logic needed to scan through main memory.

I have little doubt that the design will work under static testing but I need to run the control memory at its full 4MHz clock speed to prove the design properly, so Iíll need to contrive some sort of fast sequencer. Currently I am using an Arduino microprocessor with a USB link to a PC for tests, but that can only run the logic at a fraction of its full speed, so I need to replace it with some proper fast temporary logic built with original Honeywell logic modules. Fortunately a wire-wrapped backplane makes that relatively easy. I spend just as much time building test setups as I do building the machine itself.

Time to dress for lunch now, so Iíll have to end there.

ClausB
March 17th, 2019, 03:19 PM
A Teensy 3 might be fast enough and still provide the ease of the Arduino IDE.

https://www.pjrc.com/teensy/techspecs.html

RobS
March 18th, 2019, 08:03 AM
A Teensy 3 might be fast enough and still provide the ease of the Arduino IDE.

https://www.pjrc.com/teensy/techspecs.html

It looks like the Teensy 3 is intended to operate on 3.3 volt signals and my logic needs the full 5 volts where the Arduino is acting as a current source, not sink, so I'd need to provide some interface buffer amplifiers and also my tests currently need a lot of signal lines between the Arduino and H200. I'm using the Arduino Mega 2560 shown below mounted on an H200 patch panel so that it can be plugged into any spare backplane socket. That panel only has 33 pins available for signals, so if the interface gets any more complicated I may have to add a second panel on a cable to plug into another socket. Only the larger Teensy boards appear to have so many I/O pins as the Mega 2560.

51786

durgadas311
March 18th, 2019, 02:52 PM
Mmmmm, I can smell the phenolic resin now....

RobS
March 19th, 2019, 04:32 AM
Mmmmm, I can smell the phenolic resin now....

Actually after forty to fifty years the phenol has pretty much dried out, so it's not a problem, even with my crates containing over a thousand boards.

durgadas311
March 19th, 2019, 05:48 AM
Yeah, but I'm still going to imagine that comforting odor of "home cooking" ;-)