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NF6X
September 20th, 2016, 10:02 AM
A friend is offering me this chassis with a couple of 8" floppy drives in it. I would want it for the drives in any case, but maybe I can find a use for the whole thing. Does this card cage look like an S-100 bus to y'all?

I won't have the unit in my hot little hands for a couple weeks or so. When I do, I'll study it in more detail. If it's an S-100 chassis, then I may be interested in trying to find cards to turn it back into a functioning computer.

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Chuck(G)
September 20th, 2016, 10:14 AM
It's impossible to say without more detail of what's in the card cage.

smp
September 20th, 2016, 10:19 AM
Hi Mark,

An S-100 board is 10 inches wide.
Also, the 100 pin edge connector is offset 1 1/2 inches from one edge of the board and 2 1/8 inches from the other edge.
If you make these dimensions, it is very likely that you have some sort of custom-built S-100 chassis.
Anyway, once you get a hold of it, make sure that you check out the voltages and grounds. If those also match up with the S-100 "standard," you are probably good to go.

Sigh... Some guys get all the luck! ;-)

smp

NF6X
September 20th, 2016, 10:38 AM
Thanks!

Randy McLaughlin
September 20th, 2016, 10:51 AM
Its not a good picture of the cage but it looks like the Cromemco cage they sold for custom/industrial applications, if so yes it's an S100 buss.

Cromemco is and was very proud of their name - and if it is a Cromemco buss it will have their logo on it.


Randy

MicrocomputerSolutions
September 20th, 2016, 11:36 AM
It's impossible to tell if the cardcage is S-100 from the angle in the photos.

But, the construction looks similiar to that of many enclosures that were manufactured by Integrand Research here in CA in the 1980s and 1990s.

Integrand manufactured from the bottom up, designing and building the transformers and circuit boards that went onto the power supplies they built, and they did custom enclosures for other bus based computers and in custom colors as well as standard colors that they stocked. They sold a multitude of S-100 enclosures and disk drive enclosures. They even dabbled in PC Enclosures for Industrial and Rackmount PC Compatibles for a time before going out of business.

I can't see the power supply. If the power supply is a commercial unit, the complete mainframe is not an Intgerand, since they built they own power supplies. But someone could have bought the Integrand mainframe without the power supply, or had a special order design built, and purchased without a power supply.

Integrand enclosures were primarily sheet aluminum, and they had the ability to bend some pretty heavy stock. Many mainframes (not rackmounts) feastured wrap around covers for the bottoms and tops that wrapped around onto the sides. Most competing S-100 enclosures and disk enclosures were fabricated/bent primarily from much thinner sheet steel.

The extra cooling fan bolted onto the end of the cardcage was a feature of their "supercooled" series, and an optional for some of their other designs.

The front panel does not look like an Integrand, but the front panel is made so it can be easily replaced (Intergrand offered custom design front panels for it's products).

If the mainframe you get is not S-100, you can still probably convert to use with S-100 by replacing the cardcage and motherboard with S-100 compatible parts (and reconfiguring or replacing the power supply). Looks like a high quality enclosure and Mitsubishi M-2896-63 1/2 height 8" dsdd floppy drives. Definitely a Keeper!

If the Mitsubishi floppy drives don't work, they may be repairable, and would probably be worth repairing. Heck, if the mainframe is an Integrand, I might be interested in buying it from you, if you don;t have a use for it. I can service the drives for you if necessary. I have a couple of M2896-63 drives that have been retired with bad heads that I'm using for parts to repair other Mitsubishi drives, or I'd be interested in buying them from you for a few bucks to be repaired or used for parts.

Michael

Moonferret
September 20th, 2016, 11:47 AM
Surely I'm not the only one wondering what is in the matching chassis above it in the first photo? :)

NF6X
September 20th, 2016, 12:17 PM
Surely I'm not the only one wondering what is in the matching chassis above it in the first photo? :)

Nope, you're not the only one! ;)

roberttx
September 20th, 2016, 12:19 PM
Surely I'm not the only one wondering what is in the matching chassis above it in the first photo? :)

No. No you're not. :)

Randy McLaughlin
September 20th, 2016, 02:22 PM
No. No you're not. :)

Since I have seen a number of racks like that I would guess it was a process control system, some would be blank plates others interfaces to control industrial equipment under control of that chassis.

The rack would be developed by one company and all panels painted to match each other.


Randy

NF6X
September 20th, 2016, 02:56 PM
I've learned that the other cabinets have long since been gutted and turned into drawers. It all did come out of some old manufacturing equipment. Hopefully I can acquire the box with the floppy drives soon, and I'm crossing my fingers that there's an S-100 cage in there. If not... then, I can always find a use for more 8" floppy drives.

Chuck(G)
September 20th, 2016, 03:18 PM
That's too bad. If it's an industrial thingummy, I suspect that the odds are less than even that it's S100. Multibus and proprietary buses were more common in industrial applications. Still, not beyond the realm of possibility.

The prevailing view among major manufacturers was that S100 has too many design deficiencies. Multibus, with a regulated power supply (instead of lossy linear regulators on each board) and negative bus logic is a bit more rugged.

Randy McLaughlin
September 20th, 2016, 04:06 PM
That's too bad. If it's an industrial thingummy, I suspect that the odds are less than even that it's S100. Multibus and proprietary buses were more common in industrial applications. Still, not beyond the realm of possibility.

The prevailing view among major manufacturers was that S100 has too many design deficiencies. Multibus, with a regulated power supply (instead of lossy linear regulators on each board) and negative bus logic is a bit more rugged.

While many process control systems were other busses there were lots of S100 ones also - Cromemco had a good slice of that pie.

If you have ever seen a Cromemco system two you would know it is very happy in an industrial setting, plus cromemco had a line of industrial offshoots including a small S100 open frame cage and their single card computer to go with it.

I serviced some Cromemco's in a couple concrete plants and a huge paper mill.


Randy

Chuck(G)
September 20th, 2016, 04:35 PM
I've owned a Cromemco system, but S100 was a lousy bus for industrial applications, particularly when compared to Multibus or VME. S100 had severe drawbacks in its design.

Still, the first application of a microcomputer to industrial process that I saw was probably 1977, an Imsai 8080 running a plastics vacuforming machine. If the rig in question is something put together by a small outfit, I'll grant that it could well be S100. But a 100-position edge connector doesn't automatically mean S100--I can show examples of both a non-S100 backplane and boards using the 100 position edge connector.

Randy McLaughlin
September 20th, 2016, 06:31 PM
I've owned a Cromemco system, but S100 was a lousy bus for industrial applications, particularly when compared to Multibus or VME. S100 had severe drawbacks in its design.

Still, the first application of a microcomputer to industrial process that I saw was probably 1977, an Imsai 8080 running a plastics vacuforming machine. If the rig in question is something put together by a small outfit, I'll grant that it could well be S100. But a 100-position edge connector doesn't automatically mean S100--I can show examples of both a non-S100 backplane and boards using the 100 position edge connector.

I have seen a medical experimental lab that used an S100 buss based cards - they used the buss for power and interconnections but all the boards were custom wire-wrapped cards.

I have seen S100 computers in small process control work (Cromemco).

I have seen S100 computers in huge high end process control work (Cromemco).

Yes I have seen process control on many busses and many processors (the 1802 a favorite for really harsh environments).

Don't be fooled the S100 was a lot more common than you believe.

At one point almost every decent sized city had Cromemco computers for their TV weather - they used the a VAR based SDI setup for the graphics. I would bet some smaller stations still have them.

Just remember the movie Wargames showed an Imsai, which was mocked up with most of the S100 cards with their card edge connectors cut-off (cries a little here) but they used a Compupro in the background for all the graphics.

The S100 has touched a lot of areas.


Randy

Chuck(G)
September 20th, 2016, 06:40 PM
Look, I know about S100 stuff--I built my MITS 8800 in 1975 and still have it. What struck me even then, was the lack of common-sense engineering involved. The big advantage was that, compared to the well-engineered stuff on the market, it was cheap.

Can you imagine Sun Microsystems bringing out an S100 box?

Randy McLaughlin
September 20th, 2016, 09:42 PM
Look, I know about S100 stuff--I built my MITS 8800 in 1975 and still have it. What struck me even then, was the lack of common-sense engineering involved. The big advantage was that, compared to the well-engineered stuff on the market, it was cheap.

Can you imagine Sun Microsystems bringing out an S100 box?

The Altair started as three boards wired together with no bus. The bus was created when sales orders came rushing in. They were able to buy a bunch of 8080 chips with blemishes at a huge discount and quickly made the S100 bus warts and all.

Comparing a SUN to an S100 computer is more than unfair, the SUN is basically a single-board computer with some I/O expandability.

A bussed based system can never compete with the speed of a single-board computer like a PC or the SUN. A bus adds so much downside but has a huge high side. Try changing the basic type of processor in a SUN or a PC.

S100 is much better as a hobbyist system because all it's short falls are upsides for a hobbyist.


Randy

Moonferret
September 21st, 2016, 12:15 AM
I've learned that the other cabinets have long since been gutted and turned into drawers.

Ahh, that's a shame. Guess we will never know if it contained a prototype flux capacitor now :)


The Altair started as three boards wired together with no bus. The bus was created when sales orders came rushing in. They were able to buy a bunch of 8080 chips with blemishes at a huge discount and quickly made the S100 bus warts and all.

The 100 pin connectors were there right from the start. The boards were certainly not directly wired together. Initially it was called the Altair bus before the clone makers adopted it and it became known as the S100 bus. Very little thought was given to the organisation of the pinout other than to save vias on the CPU board.


Comparing a SUN to an S100 computer is more than unfair, the SUN is basically a single-board computer with some I/O expandability.

The early Sun 68k machines were built around Multibus. Yes, they had some RAM and I/O onboard but so do some S100 CPU boards.

inotarobot
September 21st, 2016, 02:25 AM
looking at the first photo after rotating it, I see the date on the floppy is 4-12-94

http://i.imgur.com/llGhQPH.jpg

a tad hard to make out the rest of it.

But the word Working on lh side of floppy label probably means disk was copy of a system one back then.

When you get it hopefully the rest of the floppy label text may give you some really good clues on what it was.

lowen
September 21st, 2016, 05:16 AM
...
Comparing a SUN to an S100 computer is more than unfair, the SUN is basically a single-board computer with some I/O expandability.

Hmmm, the original Stanford University Network (SUN) machine was 68K on Multibus. Even as late as the Sun4/3xx systems there was only cache RAM on the VME CPU card; I have one such system here with 32MB in four 8MB cards (populated with a metric ton of 41256 DIPs). Multibus was very common in the router space; the original cisco boxen were Multibus, as were the Proteon boxen. 68000, 68020, and 68030 were common in that space.

The S-100 bus is and was a lousy industrial bus; Cromemco (and others) took a lemon and made lemonade. Now, IEEE-696-1983 was a vast improvement, and, again, Cromemco made some fantastic products (topping out with the XXU 68020 CPU card, used even in military applications). But in terms of actual bus design Multibus and VME are far better for the electrically noisy industrial environment. As much as I like the TRS-80 Model II line, the Model II bus would have been a lousy industrial bus, too.


A bussed based system can never compete with the speed of a single-board computer like a PC or the SUN. A bus adds so much downside but has a huge high side. Try changing the basic type of processor in a SUN or a PC.

Actually not hard to do in an old SUN. This is exactly what happened between the Sun 3/xxx and Sun 4/xxx systems; many cards were upward-compatible in those early VME systems.


S100 is much better as a hobbyist system because all it's short falls are upsides for a hobbyist.

The same can be said for ISA passive backplane systems. S-100 was early and became ubiquitous in the CP/M space, and the engineering faults in the basic design can be overcome. But the merits of S-100 as a hobbyist bus aren't on trial here; the simple and basic fact is that there are better industrial bus systems, and many proprietary bus designs made it out to industry, along with many more Multibus designs.

I hope this particular chassis does prove to be S-100, as it would be a fantastic find. But the odds aren't great, unfortunately.

glitch
September 21st, 2016, 06:07 AM
S-100 bus layout does seem to lack common sense :) I guess that's what happens when you buffer a CPU's lines and drag them in the most convenient order to a random surplus edge connector! But, I've encountered a few industrial control systems around it. In addition to what's been mentioned, Dahlgren Engraving used a few custom cards and rebadged Solid State Music cards for some of their control systems. IBM apparently used IMSAIs as part of a test harness for something to do with System/370 machines, that's where these S-100 RAM boards (http://www.glitchwrks.com/2016/01/20/fsu-ram) came from. I've got a few other one-off/handmade/small run boards that I suspect were for industrial control, too.

Agreed tho, far less common than VME, MultiBus, PDP-11s, et c.

NF6X
September 21st, 2016, 06:47 AM
I think that the chassis in question came from a spin stand used in hard drive related operations. I don't recall whether it came from a manufacturer, remanufacturer, data recovery, etc., since I heard about its original source second-hand. It was in a clean room, in a bench with a massive granite surface plate on top to stabilize the equipment mounted on it; it wasn't running near anything like an arc furnace. The bench itself is now supporting several hundred pounds of lovely military surplus radios in its new home.

I'd love to have a shiny IMSAI one of these days, but I won't complain if this chassis gives me a simpler start in the S-100 world. The friend who wants it gone is planning an unrelated road trip through my area in about a week, so that's when it may be showing up. If it does prove to hold an S-100 backplane as I'm hoping, then finding a functional set of S-100 cards will be the next challenge, since eBay and I are not on speaking terms.

glitch
September 21st, 2016, 07:23 AM
Josh Bensadon's 8080 single-board S-100 computer is a good solution if you want a modern single-card solution. Many of John Monahan/s100computers.com boards are mature, solid hobby boards at this point, I've built a number of them for my personal use and for others who wanted them assembled. Plus it's all open source so you get the schematics and can acquire the KiCad files if you want to make a change or run more boards.

I'm in the process of going through some of my duplicate S-100 gear at the moment, if you have a hard time finding something let me know. In the vintage category, I'd suggest finding a Z80 single-board computer that can run 100% by itself -- CPU, RAM, ROM, serial console, all on a single board. I like the Vector Graphic ZCB for this purpose. I've got a few in "needs repair" condition, whatever they were previously used in had inadequate airflow and the regulators/filter caps are cooked.

MicrocomputerSolutions
September 21st, 2016, 09:55 AM
"...I'd love to have a shiny IMSAI one of these days, but I won't complain if this chassis gives me a simpler start in the S-100 world. The friend who wants it gone is planning an unrelated road trip through my area in about a week, so that's when it may be showing up. If it does prove to hold an S-100 backplane as I'm hoping, then finding a functional set of S-100 cards will be the next challenge, since eBay and I are not on speaking terms....".


I don't consider a IMSAI to be that Beginner friendly. The pretty Lights are fun in the beginning, BUT keeping an IMSAI Front Panel Compatible means giving up IEEE-696 features and simple expansion with IEEE-696 compatible boards.

I like the simplicity of a Boot PROM and Power On Jump to load the Operating System from floppy disk when starting up.

Newer boards that conform closer to the IEEE-696 Spec are easier to get to work together that boards designed during the early Wild West Days of S-100 Computers.

I usually recommend that Beginners start with a Board set from a single Manufacturer who supplied the Operating System already configured for the hardware. S-100 Hardware and Software is not like PC Plug and Play. It's not even as simple as PC Compatibles before Plug and Play.

Easy Vintage S-100 that is relatively simple to get working, is harder to expand once you have it working and are ready to start adding features.

Easy to get running a earlier board set that is easy to get running would be: SD Systems with the SBC 200 4mhz Z-80 processor board (has serial or parallel ports with EPROM sockets), the SD Systems Versafloppy II double density floppy controller for 5.25" and 8" floppy drives, and the Expandoram II 64K dynameic ram board. CPM-80 and SDOS (CPM 3.0) were available preconfigured for this board set from SD Systems. The drawback with this board set is that it is not IEEE-696 and getting these boards to play noce with boards from other manufacturers takes some "blue wires" and some patience. I've had a working SD System board set since the early 1980s. I still use it for testing floppy drives after I repair them. The SD Systems Monitor PROM has an excellent floppy testing/diagnostic.

A single board solution is available from Teletek, OR Advanced Digital. Both of these companies offered single board Z-80s with memory, I/O, and floppy controller. Hard drive controller was on a separate board. Some later boards offered onboard hard drive controllers as well. CPM-80 was offered preconfigured.

It's no secret that I prefer Compupro boards and Systems. Early boards are not IEEE-696, but they can be made to work with later IEEE-696 S-100 boards. Compupro never left early adopters out in the cold when they introduced newer Operating Systems and IEEE-696 boards. There are DRI Operating Systems for 8-bit and 16bit Systems, single-user, or multi-user, and multi-tasking. Compupro has a variety of different boards with processor, I/O, disk controller, multi-function support, and memory boards. Boards have high quality workmanship and high quality parts, and have withstood aging very well. Some other major Brands of parts are suffering from age related deterioration due to the poor/low quality of the materials that were used when they were built. Unfortunately the very popular CCS (California Computer Systems) boards are showing this type of problem on the circuit boards. Compupro Systems are easy to get working after reading the five minute configuration guide in the front of each Compupro Technical Manual. Boards that I sell come with an original Compupro Technical Manual. Compupro Systems are easy for a Beginner to get running, but you must read the manuals.

Compupro boards are not the cheapest, but I do offer a six-month Warranty on New and Used Boards, components and Systems. I usually have (200-300) Compupro S-100 boards in stock, plus replacement parts, and a few complete systems available for sale.

I can also customize DIR Operating Systems that were supplied by Compupro, if you need an OS configured differently than what comes of the distribution disks. Compupro DRI Operating Systems were supplied on 8" and 5.25" floppy disks with multiple copies of the Operating System preconfigured for most Compupro I/O boards as Console 0. Assembled, and unassembled version (with commented source) are on the Master Distribution Disks when you buy a Compupro Operating System. You will need RASM and Link (80 or 86) to assemble the later Operating Systems (if necessary) or ACT-80 or ACT-86 to assemble earlier versions of Compupro DRI Operating Systems.

Randy McLaughlin
September 21st, 2016, 09:56 AM
Ahh, that's a shame. Guess we will never know if it contained a prototype flux capacitor now :)



The 100 pin connectors were there right from the start. The boards were certainly not directly wired together. Initially it was called the Altair bus before the clone makers adopted it and it became known as the S100 bus. Very little thought was given to the organisation of the pinout other than to save vias on the CPU board.



The early Sun 68k machines were built around Multibus. Yes, they had some RAM and I/O onboard but so do some S100 CPU boards.

I admit it I was wrong - it was four cards wired together - when you get older somethings get a little mashed up:

"In the first design of the Altair, the parts needed to make a complete machine would not fit on a single motherboard, and the machine consisted of four boards stacked on top of each other with stand-offs. Another problem facing Roberts was that the parts needed to make a truly useful computer weren't available, or wouldn't be designed in time for the January launch date. So during the construction of the second model, he decided to build most of the machine on removable cards, reducing the motherboard to nothing more than an interconnect between the cards, a backplane"

The early SUN machines were single card computers plugged into a multibus.

The memory access speeds across a bus limits the speed of the computer - higher performance computers need the memory to be on the CPU board. This normally limits what types of devices can be added to the bus for DMA, this limitation can be overcome but it isn't easy.

In a different post it is mentioned the SUN did have a processor change, this is a chip designed to replace the Motorola chip. In this case Weitek designed a chip to replace a Motorola chip this is fundamentally different than changing a CPU board.

There were and are many different single board computers that plug into a variety of busses, in this case the bus is really more of an I/O bus. Some of these go much further and allow memory expansion but usually require slowing access way down to match the bus speed.

Many will disagree with me on there being a difference between Altairs having complete computer distribution over the bus and systems that could be expanded to one degree or another over a bus. I would say there is a huge difference.

I agree the Altair wasn't the first and may have been the worst bus design but it got into the hands of people that fundamentally changed the world where the others were too expensive and so didn't have a chance to reach so many people. I would go so far as to say without these early PC's (including a huge variety like apples II's, and so on) we would not have smart phones, tablets, nor a lot that we have now. The Altair/S100 brought out more personal designers than any of the others but all stirred interest.


Randy

Chuck(G)
September 21st, 2016, 10:12 AM
In the mid 70s, the company I was with looked at the available bus structures and immediately rejected S100. We went to a version of Multibus with a 100 pin main bus connector instead of the Multibus 86 pin one.

But no silliness with individual on-board linear regulators; we used negative logic and had a 20 address line/16 data line structure (this was before there were any 16 bit micros available) just like Multibus. We also implemented an I/O "deadman", so that if the CPU addressed a non-existent I/O port or memory address, a TRAP interrupt occurred--so it was easy to detect missing or faulty hardware. Our own memory was parity-checked; something the S100 people apparently never thought about. Our reaction was "Holy cow! These S100 people never gave a thought to memory failure?" Even the lowly IBM PC implemented memory parity.

For Sun to use Multibus on a 68K platform was remarkable--the native bus for 68K would have been Exorbus and later VMEbus. Just as with S100, vendors of various I/O cards were omnipresent--and you can still buy Multibus cards from various outlets.

glitch
September 21st, 2016, 10:24 AM
We also implemented an I/O "deadman", so that if the CPU addressed a non-existent I/O port or memory address, a TRAP interrupt occurred--so it was easy to detect missing or faulty hardware.

Ah, sort of like QBus/Unibus will trap if nothing responds to a memory access.


Our own memory was parity-checked; something the S100 people apparently never thought about. Our reaction was "Holy cow! These S100 people never gave a thought to memory failure?" Even the lowly IBM PC implemented memory parity.

North Star RAM boards, at least some of them, implemented parity memory, with the ability to generate an interrupt on error. Certainly the exception to the rule, though. The IBM FSU RAM boards I've got for S-100 use 9-bit static RAM, but ignore the ninth bit, presumably intended for parity.

Randy McLaughlin
September 21st, 2016, 10:31 AM
In the mid 70s, the company I was with looked at the available bus structures and immediately rejected S100. We went to a version of Multibus with a 100 pin main bus connector instead of the Multibus 86 pin one.

But no silliness with individual on-board linear regulators; we used negative logic and had a 20 address line/16 data line structure (this was before there were any 16 bit micros available) just like Multibus. We also implemented an I/O "deadman", so that if the CPU addressed a non-existent I/O port or memory address, a TRAP interrupt occurred--so it was easy to detect missing or faulty hardware. Our own memory was parity-checked; something the S100 people apparently never thought about. Our reaction was "Holy cow! These S100 people never gave a thought to memory failure?" Even the lowly IBM PC implemented memory parity.

For Sun to use Multibus on a 68K platform was remarkable--the native bus for 68K would have been Exorbus and later VMEbus. Just as with S100, vendors of various I/O cards were omnipresent--and you can still buy Multibus cards from various outlets.

As far as memory parity the early dynamic ram was impossible and the early static ram was luckily low density and very expensive (2102's were between $9.00 and $11.00 - constantly changing) a few memory boards had parity - never saw one that people actually paid for the extra ram chips to implement it.

The biggest difference is people went S100 computers because either people they knew were using it and price. The price of a working multibus computer was three times the cost of an equivalent S100 system.

For $621 you could buy an Altair and start playing with the switches (Imsais were both better and cheaper). You could upgrade your computer based on just putting a little money back each paycheck then buying an expansion.

Other early PC's had all in ones - low price - hook up to TV and start playing games.

Together they brought two groups of people together to revolutionize the world. They brought people that just want to use a PC and people that don't have a lot of money but want to invent/make something.

I would say the Altair revolutionized the world in a way no multibus or any other expensive system could, warts and all.

Before computers were handled by those guys on the other floor worked with and never wore jackets. And that floor was also too damn cold so best to stay away from.


Randy

Chuck(G)
September 21st, 2016, 11:41 AM
The biggest difference is people went S100 computers because either people they knew were using it and price. The price of a working multibus computer was three times the cost of an equivalent S100 system.

For $621 you could buy an Altair and start playing with the switches (Imsais were both better and cheaper). You could upgrade your computer based on just putting a little money back each paycheck then buying an expansion.

Other early PC's had all in ones - low price - hook up to TV and start playing games.

Together they brought two groups of people together to revolutionize the world. They brought people that just want to use a PC and people that don't have a lot of money but want to invent/make something.

I would say the Altair revolutionized the world in a way no multibus or any other expensive system could, warts and all.

Before computers were handled by those guys on the other floor worked with and never wore jackets. And that floor was also too damn cold so best to stay away from.

In that purely practical "computer for everybody" sense., Apple was far more successful--and with an Apple I at $666.66, you got far more for it.

Our RAM was Intel 2117 and parity checked. IIRC, this was the next iteration after the 4K DRAMs

I don't know about "impossible", but I used two 4K DRAM cards back in late 1975 from MITS; bit-for-buck, they were far more cost-effective than the SRAM boards, but trickier to design. The memory chips, however, were standard mainframe fare--nasty 22-pin 0.400" packages, but manufactured in great quantity by several vendors in the day. For MITS to add a ninth DRAM chip for parity would have been a small job; but the lack goes to the mindset. FWIW, in those early days of semiconductor memory, it was not uncommon to see SECDED implemented. Semiconductor DRAM was considered to be less reliable that core back in those days.

Al Kossow
September 21st, 2016, 12:45 PM
I
For Sun to use Multibus on a 68K platform was remarkable

It was driven by wanting to use off the self peripheral cards. The SUN project was started VERY early in the life of the 68000
In hindsight, it worked out OK since they were able to use a bunch of very useful third-party cards that they didn't have to
design, like the 3Com 10mbit Ethernet.

Weitek was never in the 68000 market. They did build a SPARC chip that was used in a couple of early models, and had a double-clocked
part sold as an aftermarket upgrade for the SPARCStation 2 and IPX.

When Sun Microsystems ported BSD to the Sun 2, they replaced the 68000 with 68010s. Most of the JAWS companies
that licensed the Stanford SUN design just used 68000s and Unisoft V7 or System V

cruff
September 21st, 2016, 03:23 PM
The early SUN machines were single card computers plugged into a multibus.


None of the Sun 1 computers that I ever used were usable as a single CPU board by itself. The frame buffer, memory and Ethernet were separate boards, and that was only when you had a larger system to serve up network disk volumes (NFS had not even been invented yet) to diskless clients. One or more disk controllers were also necessary for any local storage. If you wanted to talk to something over a serial port, that was a separate card also, as the keyboard and mouse used up the ports on the CPU card.

Randy McLaughlin
September 21st, 2016, 03:46 PM
None of the Sun 1 computers that I ever used were usable as a single CPU board by itself. The frame buffer, memory and Ethernet were separate boards, and that was only when you had a larger system to serve up network disk volumes (NFS had not even been invented yet) to diskless clients. One or more disk controllers were also necessary for any local storage. If you wanted to talk to something over a serial port, that was a separate card also, as the keyboard and mouse used up the ports on the CPU card.

You are just trying to be picky. The Altair was originally a non-bussed system but for commercialization it was made with a bus. Every part of the Altair was designed to be replaced/upgraded. Comparing it to a system that used a bus as a peripheral bus is not a real comparison. No more than comparing to modern PC's. Not to mention the price tag difference with a SUN.

All modern PC's were the result of the S100 environment (for best comparison compare the PC to a SOL-20 design and memory screw-up w 75% user 25% reserved).

The true bus environment has given way to practicality to maximize performance quite a bit of the computer is closely tied to the CPU and off bus.


Randy

Chuck(G)
September 21st, 2016, 04:55 PM
The true bus environment has given way to practicality to maximize performance quite a bit of the computer is closely tied to the CPU and off bus.

Passive backplane systems are still very much in use in industrial environments. Bus-ed systems predated S100; just ask any DEC owner.

Randy McLaughlin
September 21st, 2016, 05:05 PM
Passive backplane systems are still very much in use in industrial environments. Bus-ed systems predated S100; just ask any DEC owner.

Are you trying to put words in my mouth - I stated that the S100 wasn't the first and may be the worst. I never claimed the S100 bus invented nor was the first in anything. I also stated that high performance computers have to put so much on the CPU board, that does not exclude lower performance computers from being passive bus based machines.

The S100 bus was a big part of the PC movement of the 70's that has brought us smart phones and tablets.

The S100's influence can be seen today in any modern PC, including the apple.

Sun literally put the dot in dot come. The company invented the modern url. But what of the hardware the hardware was used in many CAD system that might be said to be seen in everything from buildings to aircraft carriers. But what influence of the SUN computer do we truly see in the world today.

As I said the S100 led directly to the PC but the SUN led to what?


Randy

Chuck(G)
September 21st, 2016, 05:12 PM
All modern PC's were the result of the S100 environment (for best comparison compare the PC to a SOL-20 design and memory screw-up w 75% user 25% reserved).

Non-sequitur to me. One may as well compare modern PCs to the Intellec 8 (which preceded the MITS box). A PDP-8 was much earlier and was a fully functional computer for $5000 in the 1960s. I don't get your point. Perhaps S100 was a parallel and perhaps important development, but bus-based systems had been around for a long time before that an undoubtedly influenced the MITS developers.

Randy McLaughlin
September 21st, 2016, 06:42 PM
Non-sequitur to me. One may as well compare modern PCs to the Intellec 8 (which preceded the MITS box). A PDP-8 was much earlier and was a fully functional computer for $5000 in the 1960s. I don't get your point. Perhaps S100 was a parallel and perhaps important development, but bus-based systems had been around for a long time before that an undoubtedly influenced the MITS developers.

I can go back hundreds of years and talk about using punch cards to program looms, or being used to census. They were important and can still be seen today.

In the 1970's a computer revolution happened. Dec was not part of it. The Intellec was not part of it SUN as a corporation was a part of it but SUN as a computer was not part of it.

The Altair was not only a part of it - it was a key part of it. Apple was a part of it. Commodore was a part of it. IBM was not a part of it - IBM joined the revolution after it was long over.

Who put computers in the average home, who provided a platform for an OS still seen in any command prompt on a PC. who provided a complete structure of a modern computer.

Before the time the IBM PC came out the revolutionaries provided:

Video display no longer teletypes or terminals (or at least very few). Friendly OS's for the masses. Cost effective computers. Can you even guess how many S100 video cards were made?

The revolution didn't start with everything listed but it did end that way. Most every home of middle income or higher had a computer, maybe a hand-full had a SUN, any DEC, or any Intellec (out of millions of households with computers).

So yes the computers we see today are from these early PC's and not from a SUN, DEC, IBM, or any other big iron company that no longer exists (even IBM no longer exists as "big iron").


Randy

krebizfan
September 21st, 2016, 08:43 PM
Some of us in the pro-DEC camp were a bit frustrated that DEC didn't move into the micros market in the 1970s. DEC was already selling single user systems for about the same price as fully equipped micros with equivalent performance. A fear of changing compensation for salespeople led to a computer industry filled with systems built around knockoffs of DEC CPUs, DEC operating systems, and DEC languages.

Chuck(G)
September 21st, 2016, 08:52 PM
Who put computers in the average home, who provided a platform for an OS still seen in any command prompt on a PC. who provided a complete structure of a modern computer.

Gary Kildall? But he wrote his first stuff for the not-very-important Intellec 8--and that computer dictated his standard distribution medium for a very long time. Not Altair hard-sectored floppies--and his system was not an Altair 8800 And much of CP/M was copied from systems such as RSTS/E--but then they didn't count, right?

You can't pick and choose your sources. History is a story of continuity and evolution, not sudden innovation.


Can you even guess how many S100 video cards were made?

Not as many as you seem to think. Even the very late Morrow systems (MD2/MD3) used terminals, as did almost every Compupro/Godbout system I ran into.

This is pointless. Let's just agree to disagree.

Randy McLaughlin
September 21st, 2016, 11:16 PM
DRI was cross compiled on everything from an MDS system to VAX's - I have some of the in-house DRI disks that includes the VAX sources.

DRI used cross development systems CP/M could never run on natively. Very similar to me developing software for a microcontroller on a PC.

Using another aspect of the computer revolution to say there was no computer revolution is strange:

And yes Compupro ended up with a video card but most every Compupro was sold for commercial use and used terminals as did most other commercial computers.

The morrow stayed with terminals because they made their own inexpensive terminals. They made computers that were cheaply made and they went out of business because commercial buyers wanted better and personal users wanted to play games that the morrow did poorly.

The fact that commercial system revolutionized computers differently than home computers isn't important. Commercial systems were DEC's, IBM's, Univac etc but in the 70's DEC was not selling and Compupro's and other S100 systems were selling like hotcakes.

The world pre-70's had lots of big iron companies, in the 70's they ignored the hobbyist systems and in the 80's their old world was gone. Only a couple of the big iron computer systems survived - and that was by following the revolution.



Randy

MicrocomputerSolutions
September 22nd, 2016, 03:52 AM
DRI was cross compiled on everything from an MDS system to VAX's - I have some of the in-house DRI disks that includes the VAX sources.

DRI used cross development systems CP/M could never run on natively. Very similar to me developing software for a microcontroller on a PC.

Using another aspect of the computer revolution to say there was no computer revolution is strange:

And yes Compupro ended up with a video card but most every Compupro was sold for commercial use and used terminals as did most other commercial computers.

The morrow stayed with terminals because they made their own inexpensive terminals. They made computers that were cheaply made and they went out of business because commercial buyers wanted better and personal users wanted to play games that the morrow did poorly.

The fact that commercial system revolutionized computers differently than home computers isn't important. Commercial systems were DEC's, IBM's, Univac etc but in the 70's DEC was not selling and Compupro's and other S100 systems were selling like hotcakes.

The world pre-70's had lots of big iron companies, in the 70's they ignored the hobbyist systems and in the 80's their old world was gone. Only a couple of the big iron computer systems survived - and that was by following the revolution.



Randy



A lot of WRONG here.

Compupro sold the most boards and Systems in the 1980s. If not for individual Users they would never have become the Company that provided advanced hardware to businesses and the scientific community. About 1/3 to 1/2 of all of my sales was to individuals and small Users. Less then 5% of my sales was complete systems to commercial enterprises. 75% to 85% of the service I billed was onsite service to businesses that I didn't sell the computers to.

Compupro sold two different video boards. At the beginning there was one, and at the end there was the PC Video. I sold more PC Video boards for use in commerical process control, than for business computers or private users.

Morrow went out of business because they DID NOT BUILD THEIR OWN TERMINALS. Morrow made the mistake of trusting Zenith who became the primary supplier of terminals to Morrow (for the Morrow Micro Decision). Zenith Data Systems kept offering Morrow, more and more credit at a time that Morrow was pouring every penny they could get their hands on (about $10 million from what I remember) into the development of the Pivot luggable computer. I met George Morrow in the early 80s at the San Jose Computer Swapmeet, and was privileged to spend a week listening to him a few years later at Morrow Dealer Training. George broke one of his primary rules when he borrowed/allowed the increasing loans and debt with/from Zenith. George states that company expansion should take place with cash, and not loans that would obligate the company to the loan company. George definitely did not trust Venture Capitalists.

Most Morrow Micro Decisions came with H/Z-29 terminals that were built off-shore with a custom built (for Morrow) less expensive terminal logic board (less features) that also eliminated the separate power supply board that was used on the Heathkit/Zenith terminals. Compupro was a early adopter of the full featured Zenith Z-29. Early versions of Compupro CDOS from 3.1 and later came with support for the Z-29 for multi-tasking and virtual console switching.

As a Morrow Supplier (and with a Traitor in place at Morrow). Zenith knew exactly where the development of the Morrow Pivot was at all times. At a critical time at the end of development, and the end of the IRS competition for the first luggable to be issued to IRS Agents, Zenith called the loans that they made at/with Morrow knowing that Morrow was not in a position to repay the loans. Zenith was competing against Morrow's Pivot with Morrow's own Pivot, renamed as the ZDS Z-171. Instead of the loans being repaid, they took the rights to the Pivot for $1 million credit that they gave George against the loans they had made to Morrow. George didn't have any choice. If he didn't agree to the sale of the Pivot design rights, Zenith would force him into bankruptcy. The Traitor was the President of Morrow Design. His name was Robert something or other. Immediately after making the deal to send the design rights to Zenith (for a fraction of what Morrow had invested), Robert left Morrow, and took up the position of President of ZDS (Zenith Data Systems).

I saw Bill Godbout at a San Jose Computer Swapmeet and he remarked about how George had gotten into a jam, and was forced to make the deal with Zenith to try and save Morrow.

A month later the IRS Contract went to Zenith, and Morrow was history.

The only Poetic Justice to this Story is that Zenith lost ownership of ZDS to it's Far East Suppliers a few years later, the same way that they destroyed Morrow. ZDS in it's greed to maximize profits at the cost of quality, farmed out manufacturing of CRT terminals to either Hyundai (or Goldstar, I can't remember which), and borrowed/got massive credit without paying in full. ZDS owed so much from borrowing without paying for products that one day when the loan was called, they could not pay, and Zenith Corporate couldn't or refused to bail ZDS out. Ownership of ZDS was transferred to the Creditor in lieu of repayment of the debt.

I worked for Heathkit in the early 1980s and had a front seat to Zenith buying, raping, and throwing away Heathkit, the destruction of Morrow, and fading away of ZDS. Zenith originally bought Heathkit to get into the computer business fast with their core TV business in a shamble they were desperate to find a profitable product. With the H-89 and H-19 terminals they bought a goldmine, and Heathkit sold every one that they could assemble the kits for. I remember that the wait for an H-19 terminal kit was 6-9 months for a kit at one time, and Heathkit was printing money for the first time ever. When Zenith bought Heathkit, they didn't know what to do with it. Zenith needed the cash being generated at Heathkit to stay afloat. Every morning the money generated in the stores the day before deposited in the bank and immediately transferred to Heath/Zenith headquarters. But Zenith did initially have idled factories in the US where the H-19 and H-89 could be built and renamed the Z-19 and Z-89, and they did know how to manufacture in larger scale than Heathkit was used to. To get the manufacturing cost down, Zenith redesigned (cheapened) the H-19 and H-89 and moved the production off-shore. Later farming out production as the cost of quality. Off-shore built Zenith terminals and computers had severe build problems (soldering was horrible).

Zenith killed the H-19 and H-89 computer in an attempt to force the adoption of the Z-100 Series of computers (the first Zenith designed computer products). ZDS tried to choke-off the supply of accessories for the H/Z-89 with high prices and low availability. This gave rise to Non-Zenith Suppliers of H/Z-89 support products. ZDS Management could not seem to accept the fact that the H-19 and H-89 were more popular with Buyers and Users. The Z-100 computers were more advanced, higher priced, and should have made a higher profit for Zenith than the Heathkit designed, aging H-19 and H-89. The H/Z-100 Series was in fact a marketing failure.

lowen
September 22nd, 2016, 06:21 AM
...
As I said the S100 led directly to the PC but the SUN led to what?


Hmmm, Android for one (by way of Java). Cisco's dominance in the internet router business directly stems from Cisco's use of the SUN (not Sun-1 or any Sun Microsystems' hardware, the original SUN machine).

ARM and SPARC stemmed from the same Berkeley RISC project, from different places (ARM was first). ARM is of course far more ubiquitous than x86 thanks to Android smartphones and tablets.

But that is far removed from NF6X's topic.

Randy McLaughlin
September 22nd, 2016, 11:51 AM
Hmmm, Android for one (by way of Java). Cisco's dominance in the internet router business directly stems from Cisco's use of the SUN (not Sun-1 or any Sun Microsystems' hardware, the original SUN machine).

ARM and SPARC stemmed from the same Berkeley RISC project, from different places (ARM was first). ARM is of course far more ubiquitous than x86 thanks to Android smartphones and tablets.

But that is far removed from NF6X's topic.

Cisco used to use SUN computers (but could have chosen any number of computers to run their software) but no longer, people used to drive Studebakers - therefore Cisco should be thankful to Studebakers?

SPARC's were RISC based (didn't invent RISC but did use one) so therefore we should all thank Studebakers for ARM computers?

SUN corporation continued work on P-System and called it JAVA (yes a much improved pseudo-machine) so an improvement on a piece of software but still not a real computer. As I said SUN was a huge force in creating the internet - but their hardware is gone and it is not influential today.

Comparing SPARC's to ARM's make as much sense as comparing them to extinct cars.

Pointing out SUN improved the p-system and used it on the internet is important but at best it shows a virtual computer is lasting longer than their real ones.

SUN was extremely popular in two major areas - servers and workstations and they were extremely good.

Cisco was started by SUN people it is no mystery why they started with that platform but they could have gone many different directions and still ended up where they are now.

SUN was a great company they did some great things - to my knowledge as a company they have two lasting items both are truly great - the url and their improvement on the p-system.


Randy

lowen
September 22nd, 2016, 04:46 PM
Cisco used to use SUN computers (but could have chosen any number of computers to run their software) but no longer, people used to drive Studebakers - therefore Cisco should be thankful to Studebakers?...

Randy, not sure why this discussion seems to have gotten under your skin. They're just computers, after all. It's not my intention to annoy you or to belittle what the Altair and clones did. Of course, it is likely that there were quite a few more Radio Shack TRS-80's out there than all S-100 system combined (source: Chris Johnston, 'The Microcomputer Builder's Bible' (1982 Tab Books) on page 39, "The editor of one of the popular computer magazines estimated that there are 500,000 existing S-100 systems,....") (The TRS-80 Model 4 alone is estimated to have sold over 500,000 (CORRECTION: Frank Durda quotes that 'over 400,000 were manufactured by 1986,' which is not the same as 400,000 sold. My error of memory)).

The source of the Johnston quote is apparently the August 31, 1981 edition of InfoWorld, page 18 (available at Google Books; search for the phrase '"number of S-100 systems" 500,000' and it's the only hit on Google). While Tandy's sales figures were tightly held, Frank Durda posted some guesstimates to comp.sys.tandy on 4/17/2005 in a thread with the subject "Looking for TRS-80 manufacturing stats."

As to the inspiration of the IBM PC's expansion slots, it's widely speculated that they were directly emulated from the Apple ]['s slots (PC Magazine, February 1984, page 122 "Apple Charts the Course for IBM" is one article speculating along these lines).

They didn't pull a Tandy, which used a real bus for several of its business machines (Model II, which, as I recall from comp.sys.tandy about 14-15 years ago, was a machine you know a bit about; Model 16; Model 12 (although it's a single-board computer with an expansion slot system); Model 16B (hybrid dual-bus approach); Model 6000; and Model 2000 (80186 and much more of a bus system than the PC and clones).

As to the Apple's slots, they are peripheral expansion slots and not a true full-bore bus, thanks to the address decoding done for each of the slots. The PC slots merged some of the best parts of the Apple peripheral slots with the S-100 (and others; IBM had long experience with many bus designs, including full mainframe channel attach (bus and tag) systems).

But I'll repeat myself: this is way off topic for the original questions, and if it needs to continue to be discussed I would suggest opening a new thread in the General Off-Topic forum (or Vintage Hardware, perhaps) to do so rather than continue to clutter NF6X's thread. I'll be glad to continue the discussion as long as you would like either via private message or in a thread other than this one. I'm not trying to be a smart aleck, Randy, and I'm definitely not just trying to get under your skin.

NF6X, sorry for the noise. I'm looking forward to you finding out what machine/chassis you have there.

NF6X
October 14th, 2016, 04:43 PM
An S-100 board is 10 inches wide.
Also, the 100 pin edge connector is offset 1 1/2 inches from one edge of the board and 2 1/8 inches from the other edge.
If you make these dimensions, it is very likely that you have some sort of custom-built S-100 chassis.
Anyway, once you get a hold of it, make sure that you check out the voltages and grounds. If those also match up with the S-100 "standard," you are probably good to go.

I just got the cabinet into my hot little hands. I only have a tape measure handy at the moment, but the card cage looks consistent with an S-100 bus based on your description. I will need to take more careful measurements, and look at the bus wiring.

33830 33831 33832 33833 33834

Chuck(G)
October 14th, 2016, 05:25 PM
Yup, that does look like an S100, simply based on the backplane power connections. Passive termination and a nice beefy power supply to boot.

Have fun!

NF6X
October 14th, 2016, 05:34 PM
Woohoo!

I was also given a 19" rack, which contains several instances of the other halves of the very nice rack slides on that S-100 cabinet. The cabinet itself used to be part of a hard disk servo writer, which was long since gutted for parts. It originally lived in a small rack built into a bench with a massive granite surface plate on top. I passed on the opportunity to get one of the surface plates because they were drilled for mounting stuff, and I would only be interested in a surface plate suitable for metrology rather than just a stable platform.

MicrocomputerSolutions
October 14th, 2016, 06:06 PM
Yup, that does look like an S100, simply based on the backplane power connections. Passive termination and a nice beefy power supply to boot.

Have fun!



Actually this is an active terminator motherboard. If you look closely at the rear of the motherboard behind the last S-100 connector you can see the termination SIPs. Mounted to the sides of the sips are TO-220 voltage regulators standing up (left and right of the SIPs), and a flat bar heatsink is bolted to the top of the TO-220s and connecting the left voltage regulator to the right voltage regulator. This is a standard feature of motherboards from Integrand Research, although I've seen it used by other companies on their motherboards as well.

Mounted to the left side inner wall of the maniframe close by the power supply you can see two I/O paddle boards mounted. There doesn't seem to be isn't enough clearance to mount them on the rear panel, explaining how they ended up mounted to the side panel.

OP, did you get anything S-100 boards with the Mainframe? Looks like the Processor board made have been from ADC (Advanced Digital) although a few other companies also used paddles boards for I/O connector on highly integrated processor boards. You might want to remove the paddle boards and see if there are any maker's marks on them. Paddle boards are quite valuable/invaluable to the people who own the boards that use them because they haven't made them in years, and the I/O circuits are often unusable with the custom paddle boards (which are not interchangeable).

If you can figure out who made the paddle boards, you can sell them on eBay, or look on eBay for the matching S-100 board/s.

Chuck(G)
October 14th, 2016, 06:12 PM
Missed the voltage regulators. I've got an Integrand system here, complete with fading blueprints that I bought back in the day. Haven't powered it up in perhaps 30 years. I seem to remember that Integrand wound their own transformers.

MicrocomputerSolutions
October 14th, 2016, 06:31 PM
I was a Dealer for Integrand from the 1980s, and used to drive up and pick up mainframes and disk enclosures directly from Integrand Research when I needed a carload, or needed them in a hurry, when Integrand had them in stock. They were not too far out of the way when I felt like going camping for the weekend at Yosemite or Sequoia National Parks. Make a call when I needed something, then drive up and pick it up, and then over to one of the Parks for a couple of days.

It always amazed me how much they did in house there. They designed the transformers for power supplies, cut the metal and stacked/laminated the plates before winding. Wound the cores, and then tested them before dipping them. Designed, built, and wired power supplies. They designed and etched the circuit boards for the power supplies and motherboards. They cut, painted, and assembled the enclosures, then dropped in the assembled power supplies and tested again.

Bulk wire, blank circuit board material, buckets of paint, raw sheet metal, and chemicals in one door, and finished mainframes and disk enclosures out the other end.

Gone now, they were the first Company I thought of when considering building limited new S-100 enclosures and power supplies.

MicrocomputerSolutions
October 14th, 2016, 06:55 PM
Get a scope and check the power outputs for ac. Old caps have a tendency to start letting ac by. I haven't had any problems with Compupro or Integrand power supplies yet, but I have seen many problems with Cromemco, and XOR power supplies.

After you have checked (and corrected) the power supply as necessary, then you'll be ready for a set of S-100 boards. You need to decide whether you want to wrench on old boards with compatibility problems (some people like that), or build new modern boards (the S100 Google Group is the place to look at those), and buy existing boards that work well from the later S-100 generation (I can help you if you want to go there).

I sell, trade, and service Compupro S-100 boards (probably have 200 new and used Compupro S-100 boards in stock, plus components), and I'm pretty close to you (Rialto).

NF6X
October 14th, 2016, 08:27 PM
All of those options sound potentially interesting, depending on what boards I trip over. I'm curious about the gear in another thread (http://www.vcfed.org/forum/showthread.php?54459-Vintage-boards-amp-computers) which might be taking an RV trip down the west coast soon. But a well-matched set of later S-100 generation boards could also be a nice option. I don't have any specific plans for the new system other than dipping my toes into the S-100 world, and assembling a functioning system that can boot off of the 8" DS floppy drives in the chassis. I haven't given the drives a close look yet, but the one on top is a double-sided drive, and I'm assuming they have a common Shugart style interface for now.

So, if I built it up with Compupro boards bought from you, what sort of system might I build up? Beyond the basic CPU + RAM + disk controller + serial port for a functional system, are there any other interesting I/O cards I might be able to put in there?

I might not get around to working on the power supply in this new chassis for a few weeks since I'm trying to focus on the Retrochallenge at the moment. Given the dangling wires I see in there, I don't know yet how complete it is, and it'll certainly need work before I could even consider applying power.

Chuck(G)
October 14th, 2016, 08:40 PM
The San Jose area was full of manufacturers of this and that. You could drive over to Bill Godbout on Zanker Road and grab what you needed. Go over to North First Street and you had Onyx+IMI and a whole raft of other manufacturers there.

But by 1980 or so, my enthusiasm for the 8080/8085 as a platform was seriously waning. Motorola was sampling the 68K, which was a whole generation past the old 8-bitters. I did some consulting work for Fortune Systems in San Carlos back then (I did their monochrome terminal) and could only marvel at a desktop unit running real Unix, program protection and all. My old company was deploying the Intel 80286 around 1982 running Xenix. Very heady times and the old stuff was mostly ignored by me.

MicrocomputerSolutions
October 14th, 2016, 11:57 PM
All of those options sound potentially interesting, depending on what boards I trip over. I'm curious about the gear in another thread (http://www.vcfed.org/forum/showthread.php?54459-Vintage-boards-amp-computers) which might be taking an RV trip down the west coast soon. But a well-matched set of later S-100 generation boards could also be a nice option. I don't have any specific plans for the new system other than dipping my toes into the S-100 world, and assembling a functioning system that can boot off of the 8" DS floppy drives in the chassis. I haven't given the drives a close look yet, but the one on top is a double-sided drive, and I'm assuming they have a common Shugart style interface for now.

So, if I built it up with Compupro boards bought from you, what sort of system might I build up? Beyond the basic CPU + RAM + disk controller + serial port for a functional system, are there any other interesting I/O cards I might be able to put in there?

I might not get around to working on the power supply in this new chassis for a few weeks since I'm trying to focus on the Retrochallenge at the moment. Given the dangling wires I see in there, I don't know yet how complete it is, and it'll certainly need work before I could even consider applying power.



I don't see many dangling wires, but I'm not there in person. I can see the 50 conductor cable for the floppy drives, and the wires that go to one of the filter caps have been disconnected/unscrewed.

With Compupro you have the choice of a couple of Z-80 processor boards (4,6,8mhz), and 8085/8088 (8085 8-bit) for 8-bit main processors. You can go with 8088, 8086, or 80286, or 68K 16-bit main processor boards.

The Disk-1 is a 8" floppy only disk controller (using a Disk-1 in a system with a Disk-3 hard disk controller requires the Disk-1 to read in a Boot Loader off floppy before switching to the Disk-3 to complete system boot). The Disk-1A and Disk-1B are capable of booting 5 1/4" 8" floppy drives, and will allow direct boot to 5.25" MFM hard drives when using the Disk-3 hard disk controller (without loading a boot loader of a floppy drive).

There is the Disk-2 8" hard drive controller if you want to run 8" SA-1000 interface hard drives.

The Disk-3 is a MFM hard drive controller that will control up to four MFM hard drives.

You can run CPM-80 for an 8-bit single-user OS. If you want to run a 16-bit OS, you can choose between a single-user, or multi-user OS, and single task or multi-tasking, or multi-user, multi-tasking with CPM 86, CCPM-8/16, MPM-86, and CDOS 8/16, OR MSDOS. Early OS run non-interrupt-driven, and later OS run interrupt-driven.

If running a 16-bit OS, you can run 8-bit (SPU-Z 8mhz Z-80H with 64K or 256K memory onboard and dual serial ports) and 16-bit (SP-186 10mhz 80186 with 512K memory onboard and dual serial ports) slave processor boards.

For I/O you have the choice of Interfacer-I (dual serial, non-interrupt driven) or Interfacer-II (single serial, triple parallel non-interrupt driven) or Interfacer-3 (interrupt-driven 8-port serial), or Interfacer-4 (interrupt-driven triple serial and dual parallel ports) or SPIO (intelligent 8-port serial I/O board, downloads I/O overhead onto built-in 8085 processor).

If running MSDOS, you can run a PC Video Board which uses a standard IBM Compatible RGB monitor and keyboard as one console.

You can also run the other S-100 compatible boards made by other companies (A to D converter, D to A converters, video, relay controllers, etc...) but these boards are not support by Compupro supplied OS. S-100 OS are not Plug N Play unless you stick with one manufacturer, and that Manufacturer happens to support all of the boards they made/makes in the version/s of OS they choose/chose to market/supply.

NF6X
October 15th, 2016, 12:26 AM
A Z-80 floppy based CP/M system would be fun. Would I need a separate RAM board, or is RAM included on the newer Z-80 boards?

MicrocomputerSolutions
October 15th, 2016, 01:39 AM
A Z-80 floppy based CP/M system would be fun. Would I need a separate RAM board, or is RAM included on the newer Z-80 boards?

On Compupro Systems, the System memory is always on a separate/dedicated memory board. Slave processor boards have their own memory, since they are capable of operating independently of the main processor board, but are able to access the main system memory as well as the memory on the slave processor board.

The first S-100 System that I completed used a SD Systems three board syste. The SBC-200 processor board, which had serial and parallel I/O ports on the processor board, along with sockets for four PROM/RAM chips. The Expandoram II 64K dynamic ram board, and a Versafloppy II double-density 5.25 & 8" floppy controller board. All three boards turned out to be very popular, but like many early S-100 boards that were not totally IEEE-696 Standard, and some work had to be done to use them with other early S-100 boards.

There are later processor boards that are highly integrated, that were fairly successful (Teletek, and Advanced Digital were two). I never messed with highly integrated boards again after buying the SD Systems boards, because trying to make them work with boards mixed manufacturers left a bad taste in my mouth. Which is why I switched to Compupro. Compupro offered all the perpheral boards/accessories that I was interested in, with the bonus that their OS supported all of their boards. Writing drivers and making incompatible boards compatible are not my favor past times.

A minimal non-interrupt-driven Compupro System would consist of a processor board, and I/O board, a memory board, and a floppy controller board. A minimal interrupt-driven Compupro System would consist of a processor board, a System Support-1 multi-function board (contains interval and interrupt times, real time clock, RAM and ROM sockets, and a serial port), memory board, and a floppy controller board. Add a OS, and combine with your 8" floppy drives, mainframe, and a terminal, and you have a working computer.

Chuck(G)
October 15th, 2016, 07:19 AM
On the subject of Compupro boards, I should mention that I still have about a dozen National Semi NSC800 CPU chips NOS. If you've got a Compupro 85/88 CPU board, there was an article published in one of the rags (Microcomputing, maybe?) about fitting the NSC800 in place of the 8085, giving your system the Z80 instruction set. I don't recall the details, but I think it involved just a couple of SSI ICs in addition to the 800.

NF6X
October 15th, 2016, 08:46 AM
An interrupt-driven system sounds appealing because "better", but I don't understand the distinction yet in terms of what software and OSes would work on an interrupt-driven vs. non-interrupt-driven system.

My first inclination would be to run something like CP/M 2.2 on a Z-80 floppy system, but that is largely driven by not knowing a lot about other things people did with S-100 systems. I don't think I'm interested in x86 or MS-DOS on an S-100 system at this time (not ruling it out in the future, though!). I feel a lot more drawn to 8080/8085 or Z-80.

This learning process to figure out what I want to do with the system is already fun!

Chuck(G)
October 15th, 2016, 09:23 AM
On the subject of x80 DRI OS:

CP/M 2.2 has little to gain from interrupts. It's basically a serial-process monotasking OS. Issue a request, wait for completion.

CP/M 3.0 (CP/M "Plus") can make use of interrupts and extra (bankswitching) memory, but very few applications explicitly require 3.0.

MP/M requires interrupts and can run multiple users concurrently. However, it represents the backwater of CP/M 8-bit OS-es and can be tricky to get going unless you have someone's canned, configured version. You mostly saw MP/M in multi-user commercial applications, such as accounting, data entry, etc. It's far from perfect--which is not to blame the OS in particular. It's just that there were very few application programs specifically tailored to take advantage of MP/M features.

The big liability with 8 bit CP/M is that outside of vendor-configured systems (e.g. Tandy), there is no standard hardware platform (unless you want to consider the Intellec 8 ), nor set of standard required hardware features. WordStar and its ilk were remarkable in that you could come up with useful productivity software that could be tailored to a specific hardware configuration.

If you're thinking about 16-bit (x86) OS,there are much better evolved hardware platforms that follow the IBM PC plan, which, after all, is where most of your x86 software is going to come from.

There were other 8-bit OS, such as TurboDOS, but most of those aren't particularly open system and modifying to run on a specific platform can be very tricky.

MicrocomputerSolutions
October 15th, 2016, 09:24 AM
A lot of people stay with 8-bit processors and non-interrupt-driven systems (compatible with older boards). Compupro made two different Z-80 boards. The CPU-Z 160 board which was a an early board, with only late revisions capable of operating interrupt-driven. Available with 4 and 6mhz clock speeds with a switch to drop down to 2mhz and a IMSAI front panel socket, if you want to run a front panel (using a front panel limits processor speed to 3mhz). Later, Compupro offered the CPU-Z 458 board which eliminated the front panel compatibility, and used a X-80H with a top speed of 8mhz.

I think most people move up to 16-bit interrupt driven systems eventually. I like the advantage of being able to run virtual consoles and multiple applications in real time.

The 8085/8088 Dual Processor board (I usually have a 6mhz/10mhz Dual Processor board installed in my computer) allows you to boot both 8-bit and 16-bit OS, sometimes without any reconfiguration (depending on the switch setting on the floppy controller and the boot loader for the operating system. By using different versions of the floppy boot loaders, I'm able to boot CPM-80, CPM-86, CCPM 8-16. MPM-86, and CDOS all without reconfiguring anything in the computer off the floppy drives. It does not boot as fast as if I was running a 286 processor, but the SPU-Z (8MHZ Z-80H) and SP-186 (10mhz 80186) allow me to run fast application programs if that is my aim.

Still other people like running multi-user applications.

There really isn't anything wrong with whatever you choose to do.

An interrupt-driven system is also capable of running non-interrupt-driven. Not a choice to have to make unless you want to run old boards that don't implement interrupt circuitry, and don't want to re-engineer them to work with interrupts (if possible).

If you choose a non-interrupt-driven I/O board to begin with, you can still install a System Support-1 board to use the other functions, and if you decide to go interrupt-driven, switch to the serial port on the System Support-1 board as Console 0 (if you have been using a Interfacer 1 or Interfacer-2 as Console 0). If you need more interrupt driven I/O ports you will need to add a Interfacer-3 or Interfacer-4 I/O board.

lowen
October 15th, 2016, 10:12 AM
NF6X, if you're interested in a 'modern' vintage S-100, take a look at some of the S-100 stuff on http://www.retrobrewcomputing.org and see what you think.

The Compupro kit was high-quality; many of the Godbout designs were built by Compupro as I recall (and as a quick perusal of 'The Microcomputer Builders Bible' by Johnston shows (lots of pictures, including the Teleteck FDC-I load CPU card, one of the CPU-Z boards (pic isn't sharp enough to tell which one), the original Altair 8080 CPU for the 8800, and others) that to be true, with the Godbout Econoram II 8K static card pic being clear enough to make out both the Godbout and Compupro logos.

The fastest and most capable S-100 CPU actually made, back in the day, was, as I recall, a 68020 or 68030. But you can get a modern 6502 S-100 CPU card if you were to really want one.

A great source of information is Herb Johnson's S-100 section of his larger site at http://retrotechnology.com/herbs_stuff/s100.html

NF6X
October 15th, 2016, 10:28 AM
The ability to run either CP/M 2.2 or CP/M 3.0 sounds fun. The possibility of building a front panel also sounds neat. So, the imaginary system inside my head presently looks like this:


CPU-Z 160 "late revision" with interrupt support
some random 64k RAM board
System Support 1
Interfacer-4
Disk-1A
empty slot for future fun
empty slot for future fun



Would that be a practical system?
If so, are all of those items available in the MicrocomputerSolutions pile, which I can only imagine is comparable to a dragon's treasure hoard?
And if so, how many kidneys would I need to sell to acquire such a board set? :)

Thanks for the Herb Johnson link. I've also been looking things up at http://www.s100computers.com

I'm feeling an urge to covet one of the SOL systems listed in another thread if they're not too pricey, but that would be an independent project from building up the chassis I acquired yesterday. But now it just occurred to me that if I did buy a SOL, then it might be more fun to build something very different in my new S-100 chassis. So maybe one of the non-8080/8085/Z-80 options would be back on the table?

Chuck(G)
October 15th, 2016, 10:56 AM
If you're going to lay out for boards that you don't yet have, consider the more advanced integrated S100 boards, such as the Teletek Systemmaster II--fast Z80H CPU, 128K of DRAM, floppy, serial parallel on a single board. All you'd really need is a hard disk/CF interface board and you're good to go.

NF6X
October 15th, 2016, 11:03 AM
That Teletek board looks neat, assuming I could find one. If I do end up acquiring one of those SOL-20 systems in another thread, then that could fill the vintage S-100 niche in my collection and I would then be more inclined to consider a more modern S-100 system in my new chassis. So many cool options!

smp
October 15th, 2016, 11:22 AM
If you're going to lay out for boards that you don't yet have, consider the more advanced integrated S100 boards, such as the Teletek Systemmaster II--fast Z80H CPU, 128K of DRAM, floppy, serial parallel on a single board. All you'd really need is a hard disk/CF interface board and you're good to go.

Just to add my two cents worth, I suggest that if you presently do not have any S-100 boards at all and you want a stable platform to start with, you might consider Josh Bensadon's JAIR-8080. Here's a link to a current eBay offering:

http://www.ebay.com/itm/S-100-CPU-Card-8080A-SBC-or-Replacement-for-ALTAIR-8800-or-IMSAI-8080-runs-CP-M-/252544925260?hash=item3accd9be4c:g:aNUAAOSwRgJXkE1 N

The complete description is available at www.s100computers.com:

HOWEVER, Josh is available via the S100 Computer Google Group (https://groups.google.com/forum/#!forum/s100computers) and if you contact him directly, he will offer you a significant discount from the eBay pricing (I know because that's what I did).

http://www.s100computers.com/My%20System%20Pages/8080%20CPU%20Board/8080%20CPU%20Board-Old.htm

This board is a complete 64K single board computer *with* solid state disk drives and CP/M available on the SD Card. It is completely configurable, so you can enable or disable the CPU, some or all of the memory, some or all of the I/O, and also the Disk I/O. This to allow you to mix and match with whatever vintage boards you may acquire, or any of the new S-100 boards that are also available.

This would give you a complete system to start with and add on whatever you acquire in the future.

Just my suggestion. I have one, and I am loving playing around with it.

Good luck!
smp

NF6X
October 15th, 2016, 11:40 AM
Josh's board looks like an interesting option. I'll add that to my list of boards to consider. I would buy it off eBay in any case, because eBay and I are not on speaking terms. After leaving eBay in a huff around a year ago over some undesirable terms of service changes (which they subsequently retracted after the ensuing uproar), it appears that I am now banned from rejoining eBay.

NF6X
October 15th, 2016, 03:57 PM
I decided to make an offer on one of those SOL-20 computers. It'll be nice if the seller and I reach a deal, but I'll be building up my new S-100 cabinet either way.

Regarding the "loose wires" I mentioned earlier: Some wires were unscrewed from the main filter capacitor, and the harness that provides power to the S-100 backplane is missing. I haven't examined the power supply in detail yet to determine its condition and completeness, but I'll be fabricating at least one cable harness. The floppy drives are made by Mitsubishi, but I haven't written down the model number yet.

That JAIR-8080 CPU card looks like a neat and versatile option for me to consider. I think I'd still need at least a floppy controller to go with it.

NF6X
October 15th, 2016, 06:33 PM
It has come to pass that I shall be buying a SOL-20 in a little over a week. Yay! I assume that the keyboard will need rebuilding at the very least, so with the distraction of my Retrochallenge project, it may be a while before I bring it back to life. I have a number of composite monitors which should work with it, but none that will look Just Right sitting on top of it. It never ends, does it? :)

So with the vintage S-100 niche being filled nicely by a SOL-20, I feel a lot less constrained in configuring the chassis that I adopted yesterday. I may let my bank account scab over a bit before I buy the boards to outfit my empty chassis, but I'm looking forward to the eventual first smoke test.

MicrocomputerSolutions
October 15th, 2016, 08:19 PM
Take photos of the connectors on the power supply board, and on the motherboard, and measure the length of the wire that you need. I have some Integrand Research wiring harness parts left in stock, and I may have what you need.

I have the Compupro S-100 boards you were asking about, except for the CPU-Z 160 (look for a K). If you are planning on running a front panel, you can't use just any 64K memory board. Whatever you get needs to be IMSAI Compatible. Many or most 64K memory boards are not IMSAI Compatible. The IMSAI Front Panel is not IEEE-696 compatible. Any 64K memory board you buy has to be IMSAI Front Panel timing compatible, if you intend on running a Front Panel in the future. Compupro sold one 64K static memory board, the Ram-17, which had a IMSAI Compatibility Mode acessable by setting switches. There are a couple of Compupro CPU-Z 160 boards on eBay right now with asking prices between $110-$150. I don't know what speed the processors are running at, as I did not read the crystal markings.

The Mitsubishi 1/2 height 8" floppy drives are M2896-63 probably made in 1983 or 1984.

NF6X
October 15th, 2016, 08:39 PM
Take photos of the connectors on the power supply board, and on the motherboard, and measure the length of the wire that you need. I have some Integrand Research wiring harness parts left in stock, and I may have what you need.

Oh, cool. I should be able to take pictures tomorrow. I think the cabinet will probably fit in the little short rack I have sitting next to me at this very moment, presently just serving as an end table for the RL02 I'm working on for Retrochallenge.


I have the Compupro S-100 boards you were asking about, except for the CPU-Z 160 (look for a K). If you are planning on running a front panel, you can't use just any 64K memory board.

Front panel compatibility isn't a must; I was just trying to keep my options open. I'd like to get a real IMSAI someday anyway when I feel like spending IMSAI amounts of money.


The Mitsubishi 1/2 height 8" floppy drives are M2896-63 probably made in 1983 or 1984.

Is that a good model of drive? They look nicely made at first glance.

MicrocomputerSolutions
October 15th, 2016, 11:11 PM
Oh, cool. I should be able to take pictures tomorrow. I think the cabinet will probably fit in the little short rack I have sitting next to me at this very moment, presently just serving as an end table for the RL02 I'm working on for Retrochallenge.



Front panel compatibility isn't a must; I was just trying to keep my options open. I'd like to get a real IMSAI someday anyway when I feel like spending IMSAI amounts of money.



Is that a good model of drive? They look nicely made at first glance.


The Mitsubishi M2896-63 is one of the best of the 8" floppy drives available. Probably the best or 2nd best of the 1/2 height 8" floppy drives. Certainly the best of the more available 8" 1/2 height floppy drives. The only thing I don't like about the Mitsubishi 1/2 heights is Mitsubishi's use of hybrid composite chips. A dead composite can signal the end of the logic board is a donor board is not available. Fortunately the Mitsubishi hybrids have proven to be durable parts. The floppy disk eject mechanism can become flakey on heavily used drives. Being made of primarily plastic parts, replacement can be problematic.

I think everybody who plays with old computers dreams of owning an IMSAI, entering programs by switches, and watching the blinking lights. Some people enjoy entering programs on the front panel switches. Other people get bored with using the switches pretty quickly.

I'm afraid I'm of the later category. After less than six months of owning a Fulcrum (IMSAI exact clone), I'm getting bored with the lights, and never even started entering programs using the switches.

I think it's like the way most car guys dream of owning and driving an old British car (Triumph, Sunbeam, Jaguar, MG). The harsh reality of the strange engineering designs, and poor workmanship quickly surpass the feeling of accomplishment after a guy finally gets one. Yes, as a young man I wanted an MG, even though my older brother warned me not to, and I bought one. Keeping that thing running was a full time job.

Having an operating front panel means strange timing which makes compatibility a problem when trying to expand the system. Slow processor speed required by the introduction of the front panel. No extended addressing, so limited to 64K of memory. If you want to run a front panel computer, and are willing to live with the limitations, and like to enter programs using switches, then an IMSAI might be great fun to you.

I don't see many IMSAI's that are pure IMSAI. The whole concept was expandability anyway. If you just want to play with a IMSAI type front panel, consider looking for a Fulcrum IMSAI Clone. They were built using some original IMSAI parts oeftover after IMSAI's bankruptcy, stirred with some new parts built to the original IMSAI designs. The best part is that while many/most parts are interchangeable, the price of a Fulcrum in excellent condition is much less severe than buying a beat IMSAI.

NF6X
October 16th, 2016, 09:34 AM
I think that you are correct; I would probably look at an IMSAI a lot more than I would toggle in programs!

DDS
October 16th, 2016, 11:34 AM
Altair 8800 and IMSAI 8080 prices have a certain name recognition component. As a possibly cheaper clone you might want to also keep your eyes peeled for one of these:

http://www.chookfest.net/computers/z1.html

NF6X
October 16th, 2016, 11:48 AM
Altair 8800 and IMSAI 8080 prices have a certain name recognition component. As a possibly cheaper clone you might want to also keep your eyes peeled for one of these:

http://www.chookfest.net/computers/z1.html

I wasn't aware of that clone. It looks just as lovely as the original IMSAI machines. Thanks!

glitch
October 16th, 2016, 03:17 PM
IIRC it is in fact a real IMSAI chassis, sourced from IMSAI by Cromemco for their first system product. I've also seen them sold as some sort of TV/video control or generation equipment -- maybe a subtitle overlay system?

I use my IMSAI probably more than any of my other S-100 systems, but primarily for debugging (hardware and software). The front panel is really the thing you want (once you've repaired it!) for quickly and efficiently fixing low-level hardware problems on older S-100 boards. Not that it's required, I didn't have a front panel system for a long time. I do use the front panel for a development aid as well, but I don't typically do any "serious" programming through it.

The comparison with old cars is apt -- same thing with people who think they want an old Jeep or an army truck. Many people find out they don't want to use something like that as a daily driver after they've sunk a bunch of money into it. Personally, I *like* my old 3-speed M38A1 Jeep with manual brakes and no power steering, but I also use front panels :)

NF6X
October 16th, 2016, 03:22 PM
I wrote up a short blog post, including high-res pictures of the innards of the chassis:

http://www.nf6x.net/2016/10/an-s-100-computer-chassis/

What I assume is the backplane power supply harness connector is a 9-pin plug. The backplane has a 3-pin and a 4-pin connector. It looks like a power harness would need to be about two feet long.

Speaking of M38A1 jeeps, I have a 1964 USMC M38A1 waiting for me to get around to working on it again.

glitch
October 16th, 2016, 04:59 PM
Speaking of M38A1 jeeps, I have a 1964 USMC M38A1 waiting for me to get around to working on it again.

So yeah, a front panel might be for you then :)

Mine's titled as a 1952 CJ-5 on a reconstruction VIN from the previous owner, fun trick since they didn't make CJ-5s in 1952! Still has the crossmember for a machine gun/cannon mount though, and M38A1 tub/grill/et c. Looks like it'll be getting full project attention this winter, since I just sold another project vehicle rather than continuing to put money into it (1993 F250, so not that interesting anyway).

Back on the topic of your empty apparently S-100 chassis, I still have a few Vector Graphic ZCBs in the "to repair" drawer. I can fix them or you can fix them, if you're interested. Sounds like you're thinking a complete CompuPro board set is what you want though, which is an excellent choice.

NF6X
October 16th, 2016, 05:03 PM
When my attention turns back towards my military vehicles, I plan to outfit my M38A1 with an AN/PRD-1 direction finder set.

MicrocomputerSolutions
October 16th, 2016, 06:18 PM
I wrote up a short blog post, including high-res pictures of the innards of the chassis:

http://www.nf6x.net/2016/10/an-s-100-computer-chassis/

What I assume is the backplane power supply harness connector is a 9-pin plug. The backplane has a 3-pin and a 4-pin connector. It looks like a power harness would need to be about two feet long.

Speaking of M38A1 jeeps, I have a 1964 USMC M38A1 waiting for me to get around to working on it again.


The power connectors definitely look like parts used by Integrand. I'll take a look in my parts drawer in the shop later on in the week, and see what I can dig up. Most of the cables that I have were from disk enclosure power supplies, so I might have a cable with the right connector at the power supply, but with the wrong connector/s (floppy or hard drive connectors) on the other end/s.

NF6X
October 16th, 2016, 06:21 PM
Thanks for checking! I think those are plain old Molex connectors, so I can build a cable if you don't already have an exact one sitting around.