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IBM 5170 Extended Memory Card Mystery

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  • modem7
    replied
    Originally posted by djfitzgerald View Post
    So, I'll do y'all one better
    ...
    ...
    Thank you.
    I have added the documents to minuszerodegrees.net, specifically, [here] and [here].

    Leave a comment:


  • djfitzgerald
    replied
    So, I'll do y'all one better

    First off, I can confirm that the card that the OP is describing is in fact an IBM Enhanced Memory Expansion Adapter for the PC-AT and PC/XT 286. My own EMEA card has the same "ASM 55X3543" inscribed on it, and the picture on minuszerodegrees.net inscribed "ASM 30F5368" also appears to be an EMEA card.

    And now, drumroll please, the end of a very old internet mystery. What about the Operator's Guide? I wrote to the IBM Corporate Archives and asked them to send me whatever materials they still had on the EMEA card. They replied by sending me OCR'd PDFs of the following documentation:

    IBM Enhanced Memory Expansion Adapter: Guide to Operations - G570-2237
    IBM Enhanced Memory Expansion Adapter: Technical Reference Manual - G570-2240
    IBM Enhanced Memory Expansion Adapter: Specification Sheet - G571-0106
    IBM Enhanced Memory Expansion Adapter: Presentation FOILS - B184-F8
    IBM Enhanced Memory Expansion Adapter: Presentation Guide - 2-19-D-3-B184-F8
    They were unable to find the Brochure (G571-0107), and the Hardware Maintance and Service manual (G570-2239). But having the Owner's Manual, Technical Reference Guide, product spec sheet, and the salesman's pitch with slides... that should be enough to get any of us started.

    That being said, the 1MB memory DIMMs I purchased online still don't work in the card, even with the correct DIP switch settings. I suspect that the EMEA card is just picky about what memory DIMMs it takes.

    Links:
    1. Guide to Operations - G570-2237
    2. Technical Reference Manual - G570-2240
    3. Specification Sheet - G571-0106
    4. Sales Presentation FOILS (presentation deck) - B184-F8
    5. Sales Presentation Guide - 2-19-D-3-B184-F8
    Last edited by djfitzgerald; September 13, 2021, 02:22 PM.

    Leave a comment:


  • bobba84
    replied
    Originally posted by modem7 View Post
    How about:

    There it is! Mystery solved, I believe!

    Leave a comment:


  • modem7
    replied
    Originally posted by bobba84 View Post
    Do I detect the slightest hint of a next character right at the edge of that picture? Maybe it says XT 286?
    How about:

    Leave a comment:


  • bobba84
    replied
    Originally posted by mikey99 View Post
    the box says that card is for the AT and XT
    Do I detect the slightest hint of a next character right at the edge of that picture? Maybe it says XT 286?

    Leave a comment:


  • krebizfan
    replied
    Originally posted by mikey99 View Post
    Very interesting, the box says that card is for the AT and XT ..... maybe this is for the XT-286
    That would be strange having an 8-bit/16-bit memory card. Are you sure the box should be paired with that card?

    Leave a comment:


  • mikey99
    replied
    Originally posted by modem7 View Post
    An 'Enhanced Memory Expansion Adapter' sold on eBay at [here].
    Has photos, including one of box.
    Very interesting, the box says that card is for the AT and XT ..... maybe this is for the XT-286

    Leave a comment:


  • ArchieX
    replied
    Originally posted by modem7 View Post
    Could it be that you have the 'Enhanced Memory Expansion Adapter', and that card is quite picky about the 1MB modules that it can use ?
    Very possible. I've read many sources that cite the 5170 was exceedingly picky with the memory it would recognize, but even in that case, I don't have other memory that will work in it for the time being. And along the lines I stated before, twelve IBM-propriety 9-chip 1MB 30-pin parity SIMMs is probably hard enough to locate as to be virtually impossible, and not a high priority of mine.

    But the info is nice to know!
    Last edited by ArchieX; March 15, 2016, 02:37 AM.

    Leave a comment:


  • modem7
    replied
    An 'Enhanced Memory Expansion Adapter' sold on eBay at [here].
    Has photos, including one of box.

    Leave a comment:


  • modem7
    replied
    Originally posted by ArchieX View Post
    Hmm. I also just found this link which also refers to a "Memory Expansion Adapter" that sounds like my card,
    The card quoted in that magazine article has to be different to the "Memory Expansion Adapter" found by yuhong. Why? Because of the dates of the two magazine articles.
    AUG86: "... last week introduced the Memory Expansion Adapter ..."
    SEP87: "... Was introduced last week ..."

    And it gives a different name to the card:

    AUG86: "... Memory Expansion Adapter ..."
    SEP87: "... Enhanced Memory Expansion Adapter ..."

    And the maximum RAM per card:

    AUG86: "... with as much as 3 megabytes ..."
    SEP87: "... memory adapter that provides up to 12 megabytes of memory ..."

    Originally posted by ArchieX View Post
    ... and mentions the fact that you would need five of these cards to reach a maximum of 15MB.
    That sentence can be interpreted differently.

    Originally posted by ArchieX View Post
    I think I'm starting to see a picture here. This card should be populated with 9-chip 256KB modules to give me 3MB, whereas for some reason I have a lucky set of 1MB modules that happen to work to give me 2MB; my other 1MB modules will not be seen by the system regardless of which memory adapter I use.
    Could it be that you have the 'Enhanced Memory Expansion Adapter', and that card is quite picky about the 1MB modules that it can use ?

    Leave a comment:


  • mikey99
    replied
    Originally posted by chulofiasco View Post
    i've got these...

    they're 512K each.
    Cool ! I like the look of these SIMMs , very vintage !

    Leave a comment:


  • mikey99
    replied
    Found my card ! it was in the AT sitting right on my garage workbench

    I checked the card and the original switch setting I had posted is correct:

    1,2,3,5,7,8 on
    4,6 off

    The memory count at boot goes up to 2560 KB
    Running the diagnostics diskette, indicates 128 KB is used to backfill the base memory to 640 KB
    This leaves 1920 KB extended memory.

    Leave a comment:


  • chulofiasco
    replied
    i've got these... 1.jpg

    they're 512K each.

    Leave a comment:


  • ArchieX
    replied
    Final update in regards to this issue. No other SIMM in my current possession will work in this PC-AT save for the single pair of 1MB Hitachi SIMMs, in either memory adapter. I have surrendered in the fact that I cannot stuff more memory into this system without investing in a matched set of IBM-proprietary 256K pairity SIMMs, but that is far from a current priority of mine.

    I did however learn much about the memory adapter that came with it, so that's a plus! It's a shame no one ever considered keeping the original manuals that came with such hardware.

    Thanks again for everyone's input! It finally put this 13-year mystery to bed.

    Leave a comment:


  • ArchieX
    replied
    Hmm. I also just found this link which also refers to a "Memory Expansion Adapter" that sounds like my card, and mentions the fact that you would need five of these cards to reach a maximum of 15MB. Meaning that it sounds like a maximum of 3MB is the limit of what these expansion cards can handle.

    I think I'm starting to see a picture here. This card should be populated with 9-chip 256KB modules to give me 3MB, whereas for some reason I have a lucky set of 1MB modules that happen to work to give me 2MB; my other 1MB modules will not be seen by the system regardless of which memory adapter I use.

    I'm using the wrong memory and I have an unrealistic expectation of how much memory I can install into this PC-AT. I have boxes and boxes of 256MB SIMMs but none are 9-chip. I might try a few of them later tonight after work just to see if they might work, for curiosity's sake. If they do, I'll be able to potentially increase my expanded memory to 3MB.

    Thanks for all the help so far, folks. I feel close to finally solving this 13 year mystery!
    Last edited by ArchieX; March 14, 2016, 02:16 AM. Reason: forgot link

    Leave a comment:

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