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JNZ
September 4th, 2015, 11:07 AM
I bought an Altair Clone from Mike Douglas half a year back, and it's pretty much the coolest (and most fun) computer I've owned. I grew up past the era of these first PCs, my earliest machine being a 286. I've created a collection of computers from the 80s: an Amiga 500 and a pimped out 1200, C64 and C64C, all my old DOS and Windows machines I had growing up, a few TRS-80 100s, and two coworkers recently gave a non-functioning Heathkit H-19 and an Osborne with a box full of software (but which has no raster).

I love owning and using computers that are the real deal, and it bothers me a bit that the Altair Clone is just a PIC24 emulating the real magic.

So, how feasible is it to buy, own, and occasionally operate an S-100 bus computer in 2015? I picture an Altair 8800 or IMSAI 8080, but I don't know the other options. I love the front panel switches and status lights, and ideally I'd have a serial board and a disk controller so I could run CP/M. What I enjoy most is writing and debugging assembly.

What's a reasonable price range, and what are the common pitfalls? Can it be trusted to run for hours at a time? Do these machines only need recapping, or are there more serious issues, like irreplaceable floppy motors failing or necessary controller firmware being unobtainable?

Also, bonus question: has anyone ever made a GPIO S-100 bus board? I make little microcontroller projects and having one of these computers bitbang I2C or just toggle GPIO pins would be the coolest thing.

(Edit: I meant buying and *operating* an S-100 computer, not buying and owning.)

Chuck(G)
September 4th, 2015, 11:23 AM
IMSAI, maybe, but Altair didn't exactly make industrial-strength systems. Compupro/Godbout is a good choice in heavy S-100 iron; I use (and still have) an Integrand box--came complete with (now faded) blueprints--there were many others. Exactly what do you propose doing with one, keeping in mind that graphics were a luxury that few systems enjoyed?

Bear in mind that I'm not what you would call a collector...others may have very different opinions.

JNZ
September 4th, 2015, 11:30 AM
Mostly hooking it up to a serial terminal and programming and debugging assembly on the real hardware. (Though I like to write in a modern editor like vim, then upload the .asm and download the .prn, .hex, and .com, using MITS' programming system II). For example, I'm currently trying to figure out how to use the emulated MITS 88-VI/RTC board in my Altair Clone, which involves lots of rewriting, debugging, and making my program more complicated.

A previous project I had was to monitor a stream of serial data and implement my own simple pattern matching, waiting for an error code to be output. If it found it, my goal was to use RTS/CTS on the 2nd SIO port to trigger a gate on a little board I made that switches a 12 VDC light, indicating that a script on my computer had entered an error state. Silly things like that.

I don't expect an 80 char graphics card or anything, as I've been led to believe they were quite rare on these systems. A serial board and any kind of interesting peripheral would give me some stuff to play with, though. Like I said, the best would be a GPIO board, if such a thing exists.

NeXT
September 4th, 2015, 01:25 PM
So, how feasible is it to buy, own, and occasionally operate an S-100 bus computer in 2015? I picture an Altair 8800 or IMSAI 8080, but I don't know the other options. I love the front panel switches and status lights, and ideally I'd have a serial board and a disk controller so I could run CP/M. What I enjoy most is writing and debugging assembly.
To answer this question on building a machine specifically, it is expensive.
I've looked into the options initially of building my own S100 machine and the cost for four S100 slots, the pre-etched PCB and a suitable power supply was going to set me back $250 and the PCB was one of those "we'll put you on a list and if we get enough orders we'll make a run and email you" kind of things.
Additionally if I wanted an 8080 CPU, 8K ram, one serial port and one 5.25" single sided floppy controller, expect at least $75 on average a card. There ARE bare PCB's for all of these you can buy but again, you are at the mercy of how long it takes for the guy to fulfull enough orders to run a batch. I have not even gotten into the addition of a front panel or an enclosure either.
Stockly's Altair Kit was expensive for a reason. Pretty much any S100 machine that fits your description on the open market will be at least $1200.

I ended up buying the AltairClone because it answers the question of how to build the front panel and enclosure (and have it look good) but the boards themselves are still the single most expensive components. I've yet to find the people I've been told sell the "S100 cards for a dime a dozen" and I'm starting to believe they do not exist anymore, if ever.

I'm sure if you knew a good board house you could probably get the PCB's made for cheaper than I can find. Most of the famous S100 cards have had their PCB layouts scanned in and uploaded for years but most shops want the layout in a file, not UV etch transparency sheets. You can even find the layout diagrams for the Dazzler in the back of its manual.

Chuck(G)
September 4th, 2015, 01:50 PM
If you can depart from the idea of an S100 machine, there are several good SBCs and Devkits for the Z80 family--many with expanded capabilities and enough peripherals to challenge you.

JNZ
September 4th, 2015, 02:06 PM
I'm sure if you knew a good board house you could probably get the PCB's made for cheaper than I can find. Most of the famous S100 cards have had their PCB layouts scanned in and uploaded for years but most shops want the layout in a file, not UV etch transparency sheets. You can even find the layout diagrams for the Dazzler in the back of its manual.

I do schematic capture and PCB layout, and with an existing board for testing and a schematic or high resolution scans it should be possible to create these boards. What's the size of a normal S-100 board, 8" by 5"? A medium run at OSH Park of that size would be $40 for each two-layer PCB, and looking at the ICs for the MITS 2SIO, I have to imagine that apart from the discretes, the ICs (if they're even available) could be $20 or more. There'd be more setup costs for doing a one-off run with possible revisions for mistakes, and I wouldn't have the ability to test the boards.

What are the existing kits you're referring to, where you see wait lists for PCBs?

Is there a market for this? If used boards are $75 to $150, I don't think it's cost effective to make new ones, even just trying to break even. Here's a lot of 5 boards for $100: http://www.ebay.com/itm/Lot-of-5-vintage-S-100-buss-computer-boards-untested-Cromemco-Vector-/311437549810?hash=item48831fe0f2

I bet it makes more sense to use modern chips to combine as many of the discrete ICs as possible, or even an FPGA, though that takes another set of skills. I bet it'd take a year or two to develop, but it might make sense to have a single S-100 board that just runs an FPGA and can emulate a few boards at once. Again, you'd need an S-100 computer just to be able to buy it, though. Is anyone working on something like this?

JNZ
September 4th, 2015, 02:12 PM
If you can depart from the idea of an S100 machine, there are several good SBCs and Devkits for the Z80 family--many with expanded capabilities and enough peripherals to challenge you.

That's an interesting idea, I hadn't considered that.

NeXT
September 4th, 2015, 02:26 PM
Is there a market for this? If used boards are $75 to $150, I don't think it's cost effective to make new ones, even just trying to break even. Here's a lot of 5 boards for $100: http://www.ebay.com/itm/Lot-of-5-vintage-S-100-buss-computer-boards-untested-Cromemco-Vector-/311437549810?hash=item48831fe0f2

That's an auction with seven days and five bids already on it. I'd take that price with a grain of salt. Just wait until the five second mark and the real horserace begins.


What are the existing kits you're referring to, where you see wait lists for PCBs?
Balmmo. (http://www.s100computers.com/index.html) ;)


I bet it makes more sense to use modern chips to combine as many of the discrete ICs as possible, or even an FPGA, though that takes another set of skills. I bet it'd take a year or two to develop, but it might make sense to have a single S-100 board that just runs an FPGA and can emulate a few boards at once. Again, you'd need an S-100 computer just to be able to buy it, though. Is anyone working on something like this?
A few of the new run boards have their designs modified to replace now hard to find IC's with much more modern components but really 7400 logic has not changed much and for the most part we are predating when small shops could afford to make their own custom chips. An FPGA in most instances if total overkill.
As for the production of such a super advanced FPGA driven all-in-one board, there's just enough demand for people to warrant the time and effort to even design the layout. Plus most of the people paying the megabucks these days for S100 are collectors and hobbyists, many of which are in it for the fact that one-peripheral-per-board is a lot easier to troubleshoot than modern nightmares with SMD.


...and frankly, it looks really out of place where you got a giant S100 board but there's two or three tiny chips making up the entire machine. (for example, the Omni USB (http://pdp8.hachti.de/projects/omni_usb/fron2.png) board) ;)

JNZ
September 4th, 2015, 02:35 PM
Haha, that Omni USB board looks like a joke someone would make in Photoshop.

MarsMan2020
September 4th, 2015, 03:21 PM
There is still an active group of S-100 builders at http://www.s100computers.com/, with a Google Group at https://groups.google.com/forum/#!forum/n8vem-s100. I have a whole stack of boards I need to get built, from an 18-slot motherboard all the way to the 386 CPU, 32MB RAM, and XGA video cards. However, building new boards can be pricey - ~$20+100 for a RAM/EEPROM board+components from Digikey. Individual S-100 connectors for a motherboard can run $4-$10 each.

There are more cost-effective options:
-Single board or two-board-stack computers like Sergey's Zeta 2 - http://www.malinov.com/Home/sergeys-projects/zeta-sbc-v2 - I built one of these plus the ParPortProp display board, it's really nice, CP/M with SD storage and a floppy controller in a nice compact package.
-The ECB-bus system, with a google group at https://groups.google.com/forum/#!forum/n8vem

(Some members of the group are in the process of moving a lot of the documentation about ECB boards to a new web host, but there is still active development going on of a new 68030 CPU board - the project is not dead).

JNZ
September 4th, 2015, 04:28 PM
That Zeta 2 SBC is adorable. I've applied to the S-100 group. I think I met the guy who runs it when he did an impromptu talk on the S-100 bus at VCF East this past April.

jgalinat
September 4th, 2015, 06:13 PM
Actually the guy that gave the impromptu talk was Herb Johnson, owner of the retrotechnology.com website and formally known as Dr. S-100. He did invite John Monahan up front to talk about some of his S-100 projects since he was in attendance. John is the man behind the s100computers.com website & projects.
Regards,
Jeff

new_castle_j
September 4th, 2015, 06:42 PM
Doesn't look like you can accept PM's yet, so send me an email, just add @yahoo.com to my username. I may be able to help get you started down the S-100 path.

JNZ
September 4th, 2015, 08:17 PM
Actually the guy that gave the impromptu talk was Herb Johnson, owner of the retrotechnology.com website and formally known as Dr. S-100. He did invite John Monahan up front to talk about some of his S-100 projects since he was in attendance. John is the man behind the s100computers.com website & projects.
Regards,
Jeff

Ah that's right! Thanks

JNZ
September 4th, 2015, 08:21 PM
Doesn't look like you can accept PM's yet, so send me an email, just add @yahoo.com to my username. I may be able to help get you started down the S-100 path.


Sent. You might have to check your SPAM folder, as it's from my own domain

MarsMan2020
September 4th, 2015, 08:22 PM
It's a super nice board, runs the Z80 at 20 mhz.

JNZ
September 5th, 2015, 11:04 AM
It's a super nice board, runs the Z80 at 20 mhz.

Does anyone make a front panel compatible with the Zeta? I'm a sucker for a cool looking enclosure with as many blinking lights and computer-ey sounds as possible. Otherwise I feel like I'm just using an emulator.

(Incidentally, I love that Mike put a fan in the Altair Clone, but I wish there was a diskette sound board already.)

JNZ
September 5th, 2015, 11:06 AM
If hobbyists would accept new S-100 products with surface mount chips (even big SOICs), the S-100 could still be feasible. Not all those vintage S-100 boards were kits after all, and in their day, they were designed to be the best capability for the dollar, not a quaint relic.

Through-hole components are too much of an obstacle course today for new S-100 board products. It just adds to component cost, assembly labor while reducing reliability if the chips were bought from nefarious electronic recyclers.

I'd buy an SMD S-100 system. I'm not proud. As long as it's not just some ARM core processor running realtime Linux at 2 GHz, but actual logic gates and such.

Chuck(G)
September 5th, 2015, 11:15 AM
Well, if you're going SMT, a moderate-size FPGA could probably contain the CPU and just about any device that you'd care for.

...and it'd still be a Z80.

JNZ
September 5th, 2015, 12:33 PM
Well, if you're going SMT, a moderate-size FPGA could probably contain the CPU and just about any device that you'd care for.

...and it'd still be a Z80.

This is true. It's always awkward when one has to intentionally limit the technology you can use so as to attempt to recreate the magic and spirit of the original. For some I suppose that means sticking to PDIP, no matter how impractical.

Ah, if only we had time machines.

MarsMan2020
September 5th, 2015, 12:45 PM
This is true. It's always awkward when one has to intentionally limit the technology you can use so as to attempt to recreate the magic and spirit of the original. For some I suppose that means sticking to PDIP, no matter how impractical.

Ah, if only we had time machines.

No front panel for the Zeta, but there is a Bus Monitor board for the ECB-bus N8VEM cards with blinking lights, and one for the S-100 boards - http://www.s100computers.com/My%20System%20Pages/SMB%20Board/S100%20Bus%20SMB.htm

Switches are a little bit harder - the panels on the Altair and the IMSAI used some tricks to "jam" the contents of the switches onto the 8080 bus - which is why later-generation S-100 systems usually didn't have switches once EPROM boards were common for bootstrapping and terminals of some kind were available to use.

One of the users on the S-100 forum has created a 3/4 scale IMSAI panel reproduction, but it only works with a handful of CPU boards and not with the more advanced stuff like the x86 boards that John M. has been working on lately - http://www.s100computers.com/My%20System%20Pages/Mini%20FP%20Board/Mini%20FP%20Board.htm.

Once you start talking about things like FPGAs and things that aren't real S-100 hardware...well Mike's Altair Clone uses a microcontroller not an FPGA, but he has spent a ton of time making it pretty much cycle-accurate to the 8080 and there are like 39 videos showing how to use it on YouTube (hours and hours and hours of video). So if I wanted blinky lights but not real hardware that would probably be what I would get.

Chuck(G)
September 5th, 2015, 01:31 PM
I am actually a bit surprised that the enhanced Z80 chips aren't more popular. They were certainly vintage: e.g. 64180, Z180, Z280, Z380...ez80. I wouldn't call the Rabbit R-series Z80-compatible as some Z80 instructions have been omitted or redefined.

JNZ
September 5th, 2015, 03:40 PM
No front panel for the Zeta, but there is a Bus Monitor board for the ECB-bus N8VEM cards with blinking lights, and one for the S-100 boards - http://www.s100computers.com/My%20System%20Pages/SMB%20Board/S100%20Bus%20SMB.htm

Switches are a little bit harder - the panels on the Altair and the IMSAI used some tricks to "jam" the contents of the switches onto the 8080 bus - which is why later-generation S-100 systems usually didn't have switches once EPROM boards were common for bootstrapping and terminals of some kind were available to use.

One of the users on the S-100 forum has created a 3/4 scale IMSAI panel reproduction, but it only works with a handful of CPU boards and not with the more advanced stuff like the x86 boards that John M. has been working on lately - http://www.s100computers.com/My%20System%20Pages/Mini%20FP%20Board/Mini%20FP%20Board.htm.


That bus monitor card sounds awesome. I've requested access to the N8VEM site. I'd like to see documentation and schematics to see exactly what it does.

So the idea is to connect the Zeta 2 to an ECB backplane, put them in some kind of card cage (I heard a 19" card cage mentioned--are there examples out there of what people use?) and then add some of these N8VEM homebrew cards? It sounds like I'll also want a PPIDE board that lets me use an IDE hard disk, though I like the idea of starting with either 5 1/4" or 3 1/2" floppy disks.

It also sounds like the only major concession when you use the Zeta is a single RAM chip instead of a board of them. What is it about the Z80 that makes it so much easier than the 8080 to create an old system with original style PDIPs and modern PCBs?

MarsMan2020
September 5th, 2015, 04:20 PM
That bus monitor card sounds awesome. I've requested access to the N8VEM site. I'd like to see documentation and schematics to see exactly what it does.

So the idea is to connect the Zeta 2 to an ECB backplane, put them in some kind of card cage (I heard a 19" card cage mentioned--are there examples out there of what people use?) and then add some of these N8VEM homebrew cards? It sounds like I'll also want a PPIDE board that lets me use an IDE hard disk, though I like the idea of starting with either 5 1/4" or 3 1/2" floppy disks.

It also sounds like the only major concession when you use the Zeta is a single RAM chip instead of a board of them. What is it about the Z80 that makes it so much easier than the 8080 to create an old system with original style PDIPs and modern PCBs?

The Zeta 2 is stand-alone only, there are several ECB single board computers, The N8VEM V2 using a classic Z80, the Mark IV using one of the "enhanced" Z80 chips, and an 80188 SBC.

You'd want something like the Mark IV (which has its own built in SD card slot for storage), and the PropIO V2 board for VGA+Keyboard. The ECB boards tend to integrate more features on a single board, while the new-build S-100 boards are more single-purpose-per-board.

One advantage of the ECB system is all the board run on 5V, so you can use a laptop-brick style 5V power supply to run the entire system - the S-100 boards still need the traditional +5/+16V dual supplies.

Chuck(G)
September 5th, 2015, 04:39 PM
It also sounds like the only major concession when you use the Zeta is a single RAM chip instead of a board of them. What is it about the Z80 that makes it so much easier than the 8080 to create an old system with original style PDIPs and modern PCBs?

If you're talking about a real 8080A, several things. The 8080A is an nMOS implementation with a 3-rail supply (+5, -5, and +12) and pretty much requires the 8224 clock generator and the (bipolar) 8228 bus controller. The address lines on the 8080A are TTL-compatible, but can sink less than 2ma, so buffers were always used. The chip count goes way up.

On the other hand, the 8080A, being nMOS was lots easier to employ than its predecessor, the 8008, which is a pMOS design.

Remember that the Z80A came more than 2 years after the 8080A, at almost exactly the same time as the 8085, a much improved 8080A version. Two-chip system implementations were possible with the 8085. To cram the extra functionality (bit-bang serial I/O, extra interrupts, etc.) the 8085 did have to multiplex the data and address buses, which required a extra 8-bit latch to un-mux for systems not using internal de-muxing.

True, the Z80 did feature a 7-bit refresh counter for DRAM, but I don't think it was as important as some people seem to think. The 8085 was pointed squarely at the microcontroller market, where lots of RAM wasn't important.

MarsMan2020
September 5th, 2015, 04:50 PM
If you're talking about a real 8080A, several things. The 8080A is an nMOS implementation with a 3-rail supply (+5, -5, and +12) and pretty much requires the 8224 clock generator and the (bipolar) 8228 bus controller. The address lines on the 8080A are TTL-compatible, but can sink less than 2ma, so buffers were always used. The chip count goes way up.

On the other hand, the 8080A, being nMOS was lots easier to employ than its predecessor, the 8008, which is a pMOS design.

Remember that the Z80A came more than 2 years after the 8080A, at almost exactly the same time as the 8085, a much improved 8080A version. Two-chip system implementations were possible with the 8085. To cram the extra functionality (bit-bang serial I/O, extra interrupts, etc.) the 8085 did have to multiplex the data and address buses, which required a extra 8-bit latch to un-mux for systems not using internal de-muxing.

True, the Z80 did feature a 7-bit refresh counter for DRAM, but I don't think it was as important as some people seem to think. The 8085 was pointed squarely at the microcontroller market, where lots of RAM wasn't important.

CrustyOMO did a single-board 8080A board - http://www.s100computers.com/My%20System%20Pages/8080%20CPU%20Board/8080%20CPU%20Board.htm - but all the first batch boards are sold and it will be a few months before he has more. It even has a built-in SD card slot for storage, 2 serial UARTS, and a parallel interfacre.

Combine that with the FPMini front panel board, and you'd have a pretty good 2-board IMSAI clone.

I am actually surprised how much new homebrew hardware there is out there!

ReActiveMicro.com
September 5th, 2015, 06:02 PM
Hello Chuck.


If you're talking about a real 8080A, several things.


Sorry for the odd-topic intrusion. Could you please contact me at: Support at ReActiveMicro dot com. I had an unrelated question and I can't seem to find a way to message you directly. Thanks!


Henry

Chuck(G)
September 5th, 2015, 07:00 PM
CrustyOMO did a single-board 8080A board - http://www.s100computers.com/My%20System%20Pages/8080%20CPU%20Board/8080%20CPU%20Board.htm - but all the first batch boards are sold and it will be a few months before he has more. It even has a built-in SD card slot for storage, 2 serial UARTS, and a parallel interfacre.

What a bizarre design--using 8212s instead of LS373 or LS374s. After those came out, I don't recall any designs using the 8212--darned things ate about half a watt IIRC.

The NS 8250s, IIRC, didn't come along until 1977 or 1978; the chip of choice was the 8251 (ugly bugger!). Signetics 2651 USARTs were probably more popular in the day--they use a smaller package and have synchronous capability. Nobody remembers the 2650 MPU today, but the 2651 and 2661 were really good chips and outlived their associated MPU.

Chuck(G)
September 5th, 2015, 08:02 PM
Speaking of which, why isn't STDbus more popular with the retro community?

MarsMan2020
September 5th, 2015, 09:18 PM
I do think that the S-100 IEEE-696 interface would be well placed on a FPGA to orchestrate; the bus is just a portal. If you treat the S-100 with more capable circuitry like the Multi-Bus systems of its day, an S-100 card cage would then be several complete SBCs that use the bus for accessing shared peripherals and processor-to-processor communications not unlike the way TurboDos sought to share processing load.

Special I/O boards are part of what made S-100 special and that would still be true, even with the processing residing on more or less SBCs on an S-100 card, they'd each be able to reserve and utilize that I/O.

And that ugly power system, is made nice today with low power components and various voltage conversion options. Even shutting down circuitry not in use makes the S-100 *toaster* a thing of the past.

The mistake that the IEEE-696 made, in my opinion, was not adding a higher density expansion bus, like Multi-Bus had. Today we could use that for high-speed serial channels or other possibilities.

If only... :)

John M's Floppy Disk Controller uses a captive Z80 of its own and custom firmware to abstract the commands needed to access multiple floppy formats into simple commands. And the Propeller Terminal board uses a Parallax Propeller chip (which has 8 microcontroller cores and onboard video generating circuitry) to drive a display with basically everything happening on 1 chip. When the new Parallax Propeller 2 comes out with more IO pins and faster speeds, I expect it will be possible to create a memory-mapped video board compatible with the IBM MDA using just address decode and the Propeller 2 chip.

I think going to the idea of a "motherboard" removed a lot of the flexibility to experiment and try new system configurations which S-100 allowed. When so much of the system is fixed to cloning an IBM PC or AT, a lot of innovation goes away.

JNZ
September 6th, 2015, 06:57 AM
I think the PCs and Macs were rushing to establish a professional computer for the everyman, and in doing so, wanted to make sure no one could ever attach any of their experimental designs. The OS made it difficult to write and integrate drivers, even though the circuitry was trivial and the card buses were easy.

I used PCs at work, but at home I found SBCs and S-100 more interesting. If I designed a AY3-8910 Programmable Sound Generator card for my S-100, writing code to make it work was easy. Never would even consider crossing the PC or Mac line in the sand with something like that. In my experience that is what killed a lot of the joy of early systems. PCs and Macs became only tools that you bought and bought cards for and bought software for and operated... everything was bound by the rules and regulations of the OS. So I never established any affection for those tools; if I like one better than a previous one, it was merely like preferring one saw or hammer better than another.

The PCs and Macs filled a need, certainly, and I exploited that tool-like utility. But it only offered joy in writing software applications under artificial IDEs. Never needed a soldering iron near them. And that's a shame. :)

I always complain that this modern generation of computing devices (smartphones, tablets) hides the underlying system to such an extent that no kid can even begin to tinker with the actual hardware, and the only thing they'll be able to do is what the operating system permits them to do. It's a walled garden. I recall feeling similarly when Windows stripped out actual MS-DOS mode. You guys, however, have the experience to take it one step further. I guess the ways things get locked down and consumerized has been a trend ever since the beginning of PCs.

griffk
September 6th, 2015, 07:11 AM
I think the PCs and Macs were rushing to establish a professional computer for the everyman, and in doing so, wanted to make sure no one could ever attach any of their experimental designs. The OS made it difficult to write and integrate drivers, even though the circuitry was trivial and the card buses were easy.
...
The PCs and Macs filled a need, certainly, and I exploited that tool-like utility. But it only offered joy in writing software applications under artificial IDEs. Never needed a soldering iron near them. And that's a shame. :)

While I agree that S-100 is the most accessible and "fun" platform for prototyping, I think you're dismissing the many routes that you could (and still can) use to do custom HW/SW on PCs using their busses (ISA and EISA, and PCI specially).

Vector, and then Jade Computer and JDR - back in the day - and now MANY on and offshore suppliers offer ready-to-prototype ISA/PCI cards (with address decoding already included on the cards), that can make a project just as easy and fun as the old S-100 variants.

Also, MS (or PC) - DOS, was no harder to extend and write drivers for, than CP/M or say, N* DOS, way back when. I am not sure what you are referring to with "artificial IDEs", but MASM and older C compilers/linkers like D-SMET and Borland, or BASIC systems and their editors or "IDEs" were just as easy to use, and even more straightforward, than any of the primitive tools we had to use with S-100 / whatever-OS-you-had platforms. (IMO :'>)

Windows and other GUIs added A LOT of obfuscation to any type of prototyping I/O communication/drivers, but even then, the first versions were fairly simple, once the paradigm was learned...

gwk

monahan_z
September 6th, 2015, 08:40 AM
Just noticed this tread, for the S100 bus I would like to point out a few further things...
The nice thing about working with the S100 bus is that you can build up a multitude of different configurations (hardware & software) by plugging in different board combinations. RAM boards from a few K up to 16MB, (much more than that with 80386/80486 boards). Even now there is a wide range of CPU's, 8080, Z80, 6502, 68000/68010, 8088, 8086, 80286, 80386, hopefully soon a 80486 and later a Raspberry module... All kinds of I/O and video boards. In most case multiple CPU can reside in the same bus. This allows one to run "hog wild" with software. One often overlooked fact is the S100 bus allows one to have better control on hardware bud identification. Dead SBC motherboards are often quite difficult to debug and if they are more that two layers or without documentation usually impossible to fix.

smp
September 7th, 2015, 08:43 AM
Hi JNZ,

You might consider starting off with something like this:

http://www.ebay.com/itm/TEI-S-100-Computer-Chassis-Complete-With-Z80-RAM-and-more/111765117004?_trksid=p2047675.c100009.m1982&_trkparms=aid%3D777000%26algo%3DABA.MBE%26ao%3D1%2 6asc%3D20131227121020%26meid%3De2d880afc2b841d4b92 6ffa5c9e8fcb2%26pid%3D100009%26rk%3D1%26rkt%3D1%26 sd%3D201422936728

This might be an inexpensive entry unit. Depending on what you find, and what you can or cannot get working, you could then continue on with some of the boards available at www.s100computers.com.

I was lucky to purchase a mostly working IMSAI some years ago ($1000), and I've since populated it with some additional vintage S-100 boards, and also purchased some of the boards available at s100computers (John Monahan).

BTW, John Monahan is an extremely helpful guy, as are many of the folks that you'll meet here on the VCF.

Good luck!

smp

g4ugm
September 7th, 2015, 09:18 AM
I always complain that this modern generation of computing devices (smartphones, tablets) hides the underlying system to such an extent that no kid can even begin to tinker with the actual hardware, and the only thing they'll be able to do is what the operating system permits them to do. It's a walled garden. I recall feeling similarly when Windows stripped out actual MS-DOS mode. You guys, however, have the experience to take it one step further. I guess the ways things get locked down and consumerized has been a trend ever since the beginning of PCs.

That's not to say there are not a huge range of systems available were you can do hardware tinkering. At a very basic level there are PIC Chips, or for general purpose i/o there is the Velleman USB board..

http://www.rapidonline.com/design-technology/usb-experiment-interface-board-electronics-kit-70-4314/

which is basically PIC based. At the next level up there are Arduino Boards, MBED boards

https://www.mbed.org/

And if you need more power then there is the Raspberry PI or the Beagle Board Black.

JNZ
September 7th, 2015, 10:20 AM
Hi JNZ,

You might consider starting off with something like this:

http://www.ebay.com/itm/TEI-S-100-Computer-Chassis-Complete-With-Z80-RAM-and-more/111765117004?_trksid=p2047675.c100009.m1982&_trkparms=aid%3D777000%26algo%3DABA.MBE%26ao%3D1%2 6asc%3D20131227121020%26meid%3De2d880afc2b841d4b92 6ffa5c9e8fcb2%26pid%3D100009%26rk%3D1%26rkt%3D1%26 sd%3D201422936728

This might be an inexpensive entry unit. Depending on what you find, and what you can or cannot get working, you could then continue on with some of the boards available at www.s100computers.com.

I was lucky to purchase a mostly working IMSAI some years ago ($1000), and I've since populated it with some additional vintage S-100 boards, and also purchased some of the boards available at s100computers (John Monahan).

BTW, John Monahan is an extremely helpful guy, as are many of the folks that you'll meet here on the VCF.

Good luck!

smp

That's an awesome looking system. The water damage is worrying, and might be worse than the seller estimates. Of course, all of these systems will need some type of repair or maintenance, it seems.

smp
September 7th, 2015, 01:48 PM
That's an awesome looking system. The water damage is worrying, and might be worse than the seller estimates. Of course, all of these systems will need some type of repair or maintenance, it seems.

Yes, I agree with your concern about the water damage description. I cannot make any of that out in the pictures shown. Those pictures show a very decent looking system. I suggest that you contact the Seller and ask if he might provide pictures of the boards individually.

If that's you bidding on the unit, I will not over-bid you. :)

smp

JNZ
September 7th, 2015, 03:14 PM
Yes, I agree with your concern about the water damage description. I cannot make any of that out in the pictures shown. Those pictures show a very decent looking system. I suggest that you contact the Seller and ask if he might provide pictures of the boards individually.

If that's you bidding on the unit, I will not over-bid you. :)

smp

That's not me bidding, so bid away. I may just monitor it and see what it goes for, as I need to get an idea for the current value of these things.

Marty
September 7th, 2015, 03:27 PM
Hi All;

I agree with everyone else, that John Monahan and others are very friendly and Helpful..
I would slightly disagree in the use of newer surface mounted stuff against the old Pins, But I have plenty of the old Ic's and bare boards and wire-wrap sockets that I would go with the old pin type of Ic's, also I cannot see good enough to use surface mounting type of Ic's, so I would suggest that use what works for You..
Also, maybe Instead of getting a case and motherboard, You might get the Boards first and then You can decide on the case type and price range you may want.. And as a side note with John's boards you can get a motherboards and other boards and get them working without an enclosure.. Also, since John's boards are about $35 to $55 each for a blank boards, without parts and you could build them up as budget and parts are available.. You would/could have a working system before You decide on the enclosure you would want..

THANK YOU Marty

JNZ
September 7th, 2015, 05:23 PM
Hi All;

I agree with everyone else, that John Monahan and others are very friendly and Helpful..
I would slightly disagree in the use of newer surface mounted stuff against the old Pins, But I have plenty of the old Ic's and bare boards and wire-wrap sockets that I would go with the old pin type of Ic's, also I cannot see good enough to use surface mounting type of Ic's, so I would suggest that use what works for You..
Also, maybe Instead of getting a case and motherboard, You might get the Boards first and then You can decide on the case type and price range you may want.. And as a side note with John's boards you can get a motherboards and other boards and get them working without an enclosure.. Also, since John's boards are about $35 to $55 each for a blank boards, without parts and you could build them up as budget and parts are available.. You would/could have a working system before You decide on the enclosure you would want..

THANK YOU Marty

This is a neat idea too. In terms of chassis, I'm drawn to metal chassis and bus monitors or other useful and unique looking front panels. Is there a standard metal component that can hold S-100 bus cards? Something I can attach a backplane (or do you call them active-terminated motherboards?) to, so that at least I'm not connecting S-100 cards on my desk?

How do I verify the operation of something like a Z80 CPU card without also configuring a memory card and SIO board? An oscilloscope?

Marty
September 7th, 2015, 05:58 PM
Hi All;

Jnz, I would need to look at John's Homepage to be sure.. But, I think in His Video's they mostly would be stand alone for initial checkout.. But, Yes, You are right You would need to get the following for a Minimal System..
A motherBoard and Power Supply, At first You could use an old PC type of Power Supply, I keep my old ones for just this reason..
A Z-80 Cpu, later, You could get other type of processors..
A Memory Board, Anything from 2K to 2 Meg, would be enough to get You started, You could add more memory later..
A Serial card of some sort, preferably two ports..
"" How do I verify the operation of something like a Z80 CPU card without also configuring a memory card and SIO board? An oscilloscope? ""
A scope would be the top of the line, but at first Led's, or a Monitor or FrontPanel Board would work just as well..
"" Is there a standard metal component that can hold S-100 bus cards? ""
After you get a motherboard, You could then measure both Length and width and height and find something on the internet, that would fit what You have.. A plane Bare chassis Would be cheaper than one that has an Old name on it, like Altair, Imsai, etc.. And later, when funds are there You could get something with a name on it..
A Desk would be Ok, as long as its Not metal, I do alot here on my Wooden Kitchen Table..
Go look at my Links for my various machines, like my PDP 11/45 or my PDP 11/40 and Yes I have an Altair 8800 and my current project my PDP 8i Clone in/with wire-wrap sockets..
THANK YOU Marty

MarsMan2020
September 7th, 2015, 07:43 PM
This is a neat idea too. In terms of chassis, I'm drawn to metal chassis and bus monitors or other useful and unique looking front panels. Is there a standard metal component that can hold S-100 bus cards? Something I can attach a backplane (or do you call them active-terminated motherboards?) to, so that at least I'm not connecting S-100 cards on my desk?

How do I verify the operation of something like a Z80 CPU card without also configuring a memory card and SIO board? An oscilloscope?

Well, if you have the Bus Monitor you would be able to use that to confirm things are happening.

A minimal Z80 system with the current s100computers.com boards would be something like:
-16 & 8V power supplies
-A backplane
-The bus monitor card
-Z80 CPU (w/onboard EPROM for the monitor)
-1MB PROM/RAM card or 4MB RAM card (1MB is simpler and cheaper to build, the SRAM chips are expensive to populate the 4MB card)
-Serial IO card

That should get you to the ROM monitor with a serial terminal. Then you could decide what other cards to add based on cost and availability of parts.

JNZ
September 7th, 2015, 07:55 PM
Thanks Marty and MarsMan2020 for that information. I don't yet have access to the N8VEM wiki (which is frustratingly private), so I can't check, but what's the availability like on the PCBs for those sorts of cards? Not necessarily all of them, but is it the sort of thing where I'll be sitting for six months waiting to have the card I need to progress to the next step in checking and building my system?

MarsMan2020
September 7th, 2015, 08:45 PM
Thanks Marty and MarsMan2020 for that information. I don't yet have access to the N8VEM wiki (which is frustratingly private), so I can't check, but what's the availability like on the PCBs for those sorts of cards? Not necessarily all of them, but is it the sort of thing where I'll be sitting for six months waiting to have the card I need to progress to the next step in checking and building my system?

There are some hosting issues with the wiki which is why it is set to private right now (all the information is still there).

The way it works is usually John M. does an initial run of a small quantity of a board that gets tested, then different people have taken "ownership" of different boards and handle getting them made and distributing them once they are "stable".

I am looking at the list right now and all the ones you would want show that people have them, but you'd probably want to send some emails and check.

JNZ
September 7th, 2015, 09:08 PM
There are some hosting issues with the wiki which is why it is set to private right now (all the information is still there).

The way it works is usually John M. does an initial run of a small quantity of a board that gets tested, then different people have taken "ownership" of different boards and handle getting them made and distributing them once they are "stable".

I am looking at the list right now and all the ones you would want show that people have them, but you'd probably want to send some emails and check.

That's pretty encouraging. Thanks!

I'm really excited about this project, but I'm going to do more research. Still, I entered this thinking my only option was to buy an original Altair for $3-6k and turn it on once a month, pretty much just rubbing a baby diaper on it like a Ferrari.

Is it unrealistic to think I could have it running most of the time, executing some program or doing a simple task? Would an ECB-based computer, like the Zeta 2 SBC or N8VEM Mark IV be more practical for this?

gekaufman
September 8th, 2015, 03:03 AM
I have the Z80 CPU, ZFDC (Floppy Controller), 4mb SRAM, 8088 and 8086 CPU PC Boards available, and others have most anything you'd need to get started. PM me and I can direct you to the correct folks and copy the availability to you.

The Zeta or Zeta2 SBC along with the Propeller card makes an easy CP/M entry.

- Gary

Marty
September 8th, 2015, 03:50 AM
Hi All;

JNZ, "" I'm really excited about this project, but I'm going to do more research. Still, I entered this thinking my only option was to buy an original Altair for $3-6k and turn it on once a month, pretty much just rubbing a baby diaper on it like a Ferrari. ""
Actually, with the new boards, and new type of power supplies, You could have it on for days at a time..
And with my Altair, I put in switching power Supplies, and left in and only disconnected the origional power supplies And so I did and could run it for hours at a time..
So, no it can run regularly, especially if You are using John's Boards..

Here is the link for the site and the Boards that are available.. Look at the video's and His links for buying the boards along with the cost of the boards..

http://www.s100computers.com/My%20System%20Index%20Page.htm

THANK YOU Marty

jharre
September 8th, 2015, 07:40 PM
Yes, I agree with your concern about the water damage description. I cannot make any of that out in the pictures shown. Those pictures show a very decent looking system. I suggest that you contact the Seller and ask if he might provide pictures of the boards individually.

If that's you bidding on the unit, I will not over-bid you. :)

smp

Hey, stop that! That's me you are bidding against. :rolleyes:

I agree that the boards could be toast, or, it might be a massive re-socketing job. Either way, it's going to be a lot of work to restore the original boards - it it's even possible.

Jim

JNZ
September 8th, 2015, 07:47 PM
Whoever wins it should have to post plenty of pictures of the restoration, complete with a video of it being resurrected!

There's simply not enough S-100 or ECB content on YouTube.

MarsMan2020
September 8th, 2015, 08:40 PM
Whoever wins it should have to post plenty of pictures of the restoration, complete with a video of it being resurrected!

There's simply not enough S-100 or ECB content on YouTube.

Mike D's Altair Instructional Videos - https://www.youtube.com/watch?v=suyiMfzmZKs&list=PLB3mwSROoJ4KLWM8KwK0cD1dhX35wILBj

JNZ
September 8th, 2015, 08:52 PM
Mike D's Altair Instructional Videos - https://www.youtube.com/watch?v=suyiMfzmZKs&list=PLB3mwSROoJ4KLWM8KwK0cD1dhX35wILBj

Mike's videos are awesome. I have his Altair Clone sitting behind me right now, running CP/M ;)

monahan_z
September 9th, 2015, 11:31 AM
Guys, I thinking of trying to solve the chicken/egg problem by doing a single Z80 based S100 board that would contain 64K RAM, EEPROM, PS/2 keyboard input as well as a host of indicator LED's and jumpers to deactivate ROM/RAM keyboard etc. one at a time as other boards are added to get new people started on the S100 bus.

The only part I'm not sure of is what to do about console output/video. Was thinking of using the basic Propeller Console IO circuit
http://s100computers.com/My%20System%20Pages/Console%20IO%20Board/Console%20IO%20Board.htm

but this requires programming its two wire serial EEPROM with Parallaxes software and USB adaptor/software. Do you think that is outside the range capability of most newcomers. Alternatively we could go with a straight serial output to some dumb terminal IBM PC terminal emulator. Open also to other suggestions.

John

Marty
September 9th, 2015, 12:30 PM
Hi All;

John, For my two cents worth, I would go with the Serial Port, as more people would find that easier to get going..
I for myself would not know how, nor have the means to program the Parallex..
And the same would probably be for the USB adaptor/software..

THANK YOU Marty

smp
September 9th, 2015, 12:38 PM
I second the motion for a simple 3 wire serial I/O port.

smp

gekaufman
September 9th, 2015, 12:42 PM
John -

The propeller console is very sweet, I'd encourage you to include it. Almost anyone who can program the boot EEPROM could also program the serial EEPROM directly. You wouldn't need the Parallax USB hookup or software unless you planned to modify the firmware.

Many of us would also be happy to program the EEPROM's up for folks getting started - and eliminate one potential source of frustration.

It might also be worthwhile to "piggyback" onto the software available for the Zeta2/ParPortProp and use the same port addressing etc. That way the RomWBW and SD card images could be used on both systems - having CP/M in ROM is rather nice.

- Gary


Guys, I thinking of trying to solve the chicken/egg problem by doing a single Z80 based S100 board that would contain 64K RAM, EEPROM, PS/2 keyboard input as well as a host of indicator LED's and jumpers to deactivate ROM/RAM keyboard etc. one at a time as other boards are added to get new people started on the S100 bus.

The only part I'm not sure of is what to do about console output/video. Was thinking of using the basic Propeller Console IO circuit
http://s100computers.com/My%20System%20Pages/Console%20IO%20Board/Console%20IO%20Board.htm

but this requires programming its two wire serial EEPROM with Parallaxes software and USB adaptor/software. Do you think that is outside the range capability of most newcomers. Alternatively we could go with a straight serial output to some dumb terminal IBM PC terminal emulator. Open also to other suggestions.

John

Chuck(G)
September 9th, 2015, 02:14 PM
On the other hand, a simple TTL-to-USB serial dongle (4 wire) runs less than $2 shipped on eBay and would probably satisfy the needs of most folks for text output. I used to build prototypes using the FTDI chips for serial-to-USB output, but given the cheap Chinese adapters, it doesn't make any sense--and you don't need +/-12 or converter (e.g. MAX232) to get RS232C signal levels.

Tor
September 13th, 2015, 11:52 PM
Hi JNZ,

You might consider starting off with something like this:

http://www.ebay.com/itm/TEI-S-100-Computer-Chassis-Complete-With-Z80-RAM-and-more/111765117004?_trksid=p2047675.c100009.m1982&_trkparms=aid%3D777000%26algo%3DABA.MBE%26ao%3D1%2 6asc%3D20131227121020%26meid%3De2d880afc2b841d4b92 6ffa5c9e8fcb2%26pid%3D100009%26rk%3D1%26rkt%3D1%26 sd%3D201422936728
ok, somebody got it? I noticed the bid doubled in the last few seconds.

-Tor

jharre
September 14th, 2015, 02:05 PM
ok, somebody got it? I noticed the bid doubled in the last few seconds.

-Tor

Yep, that was me. :D I had to clench my jaw for the last few seconds, but thankfully whoever it was ran out of time before they could top my bid at the end.

So, finally, I have an S-100 system! This will certainly be a learning experience and probably a long winter project, especially after seeing the close-ups of the boards.

Jim