Image Map Image Map
Results 1 to 5 of 5

Thread: powering up a 30+ year old S100 system

  1. #1
    Join Date
    Aug 2017
    Location
    New Mexico, USA
    Posts
    17

    Default powering up a 30+ year old S100 system

    Dug out this S100 system in the back of my garage that I purchased in the early 1980's. I remember only used them briefly. I have not power it up since. One of the three boards is Cromemco 32K Bytesaver. I don't have any information about the two of the boards. Can anyone tell me more about them? Thanks.
    Attached Images Attached Images

  2. #2

    Default

    Hi Plasmo,

    Well I really tried to locate these cards for you.

    Never heard of Trace Memory, but I can see it's a simple Dynamic memory card

    Tried hard to match the MZ80A-I/O CPU and Assembly 11-1019 legends. But nothing comes to mind. Cards with IA-nnnn are Ithaca Audio / Intersystems . You have 11. Also MZ80A is rather unfortunately close to the Sharp computer of the same name thus obscuring any Google search.

    The CPU card photo is not 100% clear but looks like an Intel (i.e. non WD) floppy controller and I can see a Z80A CPU so surmise the top connectors are serial, diskette, and say another serial/parallel


    AFTER A GOOD CLEANING, and checking the voltages on the relevant pin outs on the S100 Bus power rails I'd plug in the cpu card with memory and connect a PC with USB to serial converter into one of those IO ports and poweron and see if anything is printed out

    Anybody else recognise this CPU Multifunction card?

    regards mb

  3. #3
    Join Date
    Aug 2017
    Location
    New Mexico, USA
    Posts
    17

    Default

    Thank you for looking into the boards. The pictures I took are quite high in resolution, but I think their resolution were reduced significantly when uploaded to save space. Here is the lower quadrant of the memory board. The memory are mm5257N, I think they are 4Kx1 static RAM. It reminds me very much of the Tarbell 32K static RAM board, but it is not exactly the same. Etched in copper is the date 2-20-78, I assume it was when the pc board was made.

    Pic of the major components of the CPU board is attached. It is one of the more densely populated Z80+I/O board. IC date code are from 1980-1983. Etched in copper in the solder side is "CTC F 8316". I think the board was made in the 16th week of 1983
    Attached Images Attached Images

  4. #4

    Default

    I don't recognize the CPU card specifically but looking at the chips, I think the Intel chip in the center is an 8255 Parallel I/O, likely making the center 2x25 header a parallel I/O connector. The two smaller connectors are probably 2x13 headers for the Zilog DUAR/T (making them the dual serial ports). Not sure about the pin arrangement but I'd bet on a ribbon cable to a DE25F IDC-type connector; not sure if DCE or DTE so you may need a NULL modem adapter as well. A little probing with a continuity tester should prove out the parallel port as well.

    I agree with amouse -- pull the cards and make sure the power supply works properly; use a Variac if you have one rather than just throwing the switch. Check the cards themselves for cracked tantalum capacitors.

  5. #5
    Join Date
    Aug 2017
    Location
    New Mexico, USA
    Posts
    17

    Default

    Thank you for looking into the boards. I'm still a new member and I believe my reply a week ago was lost. Here is a repeat of it:

    The pictures I have are quite high in resolution, but I think their resolution were reduced significantly when uploaded to save space. Here is the lower quadrant of the memory board. The memory are mm5257N, I think they are 4Kx1 static RAM. It reminds me very much of the Tarbell 32K static RAM board, but it is not exactly the same. etched in copper is the date 2-20-78, I assume it was when the pc board was made.

    Pic of the major components of the CPU board is attached. It is one of the more densely populated Z80+I/O board. IC date code are from 1980-1983. Etched in copper in the solder side is "CTC F 8316". I think the board was made in the 16th week of 1983
    Attached Images Attached Images

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •