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Vector S-100 bus board

C

Crawford

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Joined
Oct 21, 2008
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Folks,

Another project jumped into my lap. At a local electronics store, I found a complete (vintage 1977) S-100 bus/motherboard kit from Vector. Since this just the PC Board, I'll be looking for cheap S-100 bus edge connectors.

I've always wanted an S-100 computer, so I guess I'm building one now. Any sage advice for what to look for in terms of boards to plug into this?

I'll probably want a Z80 CPU, some RAM, Serial I/O and a floppy controller. The eventual goal will be to run CPM.. and blinkenlights of course.

Thanks,
Crawford
 
You're embarking on quite a journey. Make sure your power is correct before you plug in any boards! NOS motherboards may have bad caps, and three-prog resistors.

I suggest that you start with all newer S-100 boards, stuff from the 80's, not the 70's. The best S-100 boards were made in 1981-1984. A Jade Z80 board would be a good start, plus a 64K static RAM board from CompuPro or SMS, etc. CompuPro was the last great S-100 board maker and even into the mid 80's you could still see their ads in Byte mag.

Once you conquer a newer, more reliable S-100 system you can then tackle an Altair or IMSAI, etc.

Bill
 
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S100

S100

Bill,

I hate to dis you but CompuPro never (?) made any dynamic RAM cards for S100 systems. Bill Godbout and many others felt that static RAM was the only way to build solid reliable systems and his product line reflects that, from early 4K boards up to later 128K models. Can't quite remember, but the 512K M Drives may have used DRAM.

I agree that the Jade BigZ makes a nice CPU since it has a built-in serial port and can accomodate a ROM monitor for simple operation and/or diagnostics.

Anyone wanting to run CP/M will also need some sort of disk controller. It would be smart to look for something that was well supported and can support soft-sector 5 1/4 disks, like the CompuPro Disk 1A or 1B, etc.

best,
Jack
 
I meant static, oops. I get the two confused, sorry! Thanks for the correction.

I am currently using a SMS "The last memory" STATIC memory 64K RAM and it has been reliable. All I have in a California Computer Systems 2200 Series S-100 computer at the moment is a JADE Z80 controller, SMS 64K RAM, and a bus terminator card. Once you find a good RAM and processor card, you can use to test the basic function of a computer.

Bill
 
I always loved static memory. After about 5 seconds, they are hot enough to literally fry an egg on. As I found out with my Vector Graphics system in 1979. If I remember, I paid something like $800 for one or two 16K static boards around then.
 
jackrubin said:
Bill,

I hate to dis you but CompuPro never (?) made any dynamic RAM cards for S100 systems. Bill Godbout and many others felt that static RAM was the only way to build solid reliable systems and his product line reflects that, from early 4K boards up to later 128K models. Can't quite remember, but the 512K M Drives may have used DRAM.

best,
Jack
Click to expand...

The MDrive-S RAMdisk board uses static RAM, not sure about other models.

--T
 
How come no one ever mentions Cromemco when they talk about S-100 boards? Among the very best quality and best supported S-100 stuff of its day, and probably one of the last companies in the business until around 1990, albeit as part of Dynatech then. CPUs from Z80 to 68030, memory boards from 4K to 2M, SCSI, networking, graphics, all sorts of good S-100 stuff.

And that's Vector Graphic if you don't mind, Chuck; no "s"! ;-)

m
 
Chuckle, I could have sworn it was Graphics. But I just looked up some pictures on the Vector-1, which I owned, and sure enough, all the pictures say "Vector Graphic, Inc.". I never can remember if it was with the s or not.

Of course, kicking my buns, as I gave away the entire setup with a working ADM 3 terminal to a neighbor when I moved in 1983.

And I did think of Cromemco immediately when I read the original post. I have some here now. They were/are great boards.
 
Speaking of Cromemco, I am testing a 64KZ RAM board. It seems to be working correctly and I agree that this is another manufacturer to rely upon. I have run some memory tests successfully. On the other hand I have a mod-ed Cromemco ZPU board, that does not detect the presence of the memory. The wait state jumpers have been changed, not sure at the moment (or probably a bunch of additional moments) what's going on. THe M1 jumper to 0 has been cut and it's instead wired to pin 4 of IC40. The voltages I think are OK and the computer itself is OK volts-wise. I don't mean to start a new thread here, just commenting that Cromemco has some good stuff, yes.
bd
 
Actually, the Cromemco RAM is not working very well after doing more thorough tests with Bob Grieb's Z80 ICE, which is made to be plugged into the Z80 slot of computer or controller card. Bob created his own "PIC-based circuit that could emulate a Z80 for displaying memory, writing to I/O ports, etc. as an aid to troubleshooting..." Bob's modern version is based on the Nicolet Paratronics Z80 emulator called the Z80 NICE. I am fortunate to have been given a beta version of this device to test.

Numerous miscellaneous read/write errors.

The bottom line is that assume NO S-100 RAM card works, even the newer ones, you should always have a way to test.
 
The 4K dynamic RAM board for the Altair was horrible. It had this "interesting" tendency to change memory if RESET was toggled. It used TI 4Kx1 (TMS4096?) DRAMs. This made for tremendous fun when the bootloader had to be toggled in via the front panel switches.

I eventually replaced my pair with a couple of 8K SSM static RAM boards that used a mess of 21L02s.

Heaven.
 
I agree about the Altair boards, but I am coming at this from the restoration angle, not the "I was there" perspective (I was too young)...
 
billdeg said:
Actually, the Cromemco RAM is not working very well after doing more thorough tests with Bob Grieb's Z80 ICE, which is made to be plugged into the Z80 slot of computer or controller card. Bob created his own "PIC-based circuit that could emulate a Z80 for displaying memory, writing to I/O ports, etc. as an aid to troubleshooting..." Bob's modern version is based on the Nicolet Paratronics Z80 emulator called the Z80 NICE. I am fortunate to have been given a beta version of this device to test.

Numerous miscellaneous read/write errors.

The bottom line is that assume NO S-100 RAM card works, even the newer ones, you should always have a way to test.
Click to expand...
---------
Of course you never know with any of this stuff where it's been or what's been done to/with it, but FWIW I never had any problems with the 64KZs and still have a number of working ones; there was a later version though, the 64KZ-II. The best way to test S-100 stuff was usually in a known working system that they were designed for, if possible; subtle differences in some of the bus signals were often the cause of problems.
Good luck!
 
I ran more tests on the KZ that indicate that the RAM may be OK after all - small address ranges test OK, but larger ones flake out in a pattern indicating that there may be an issue with the way the NICE does it's testing. I have been in contact with the designer of the Z80 ICE unit and he also suggested line noise as a possible issue.
 
The System 3 disk drive, the boot drive, does not work. I need to fix a sensor to know when a disk is present. I chose the System 1, at random, more for testing of the ICE. I have already swapped cards to and from the System 1 and 3.
Bill
 
Geez, you haven't fixed that yet? Not even swapped the drives or at least the DS jumpers?
;-)
But either way, System 1 or 3, I'd test that 64KZ with a known good set of Cromemco cards; wouldn't be the first time someone wasted a lot of time because there was a problem with the tester instead of the testee...
 
You should see my house...a never ending set of projects. I work on something almost every day, but there is always 10x more! Not complaining though. I have been looking for a Persci 299 drive, but they're hard to find.
 
Thanks for the input

Thanks for the input

Folks,

Thanks for the input. Yes I agree that Cromemco made great stuff. We programmed UCSD Pascal in college on a Z-2 I called 'Black Beauty'. Guess I just dated myself.

I held a Cromemco 16K memory card in my hand just last month. Someone had clipped off the connector (supposedly for the gold). I almost wept.

- C
 
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