Image Map Image Map
Page 1 of 4 1234 LastLast
Results 1 to 10 of 31

Thread: AT&T 6386/25 WGS Video Card?

  1. #1

    Default AT&T 6386/25 WGS Video Card?

    I recently acquired my first vintage PC as the above title. It has no video card. I searched the forum but to be honest I'm not really sure what I'm looking for!

    The mainboard is an Intel PSBC386AT25C04, if that helps. I have found some RAM for it. Can you also tell me what type of monitor I will need?

    Thanks for looking.

  2. #2
    Join Date
    Feb 2010
    Location
    Russia, St.Petersburg
    Posts
    227

  3. #3

    Default

    Thanks for that Alec, very interesting and helpful.

  4. #4

    Default

    I have removed my motherboard and found that it looks to have on-board ram. It has 8 x MCM6290P35 chips and 3 x MCM6288P25 chips. I am not sure how much each chip has. The 6288 data sheet says 16x4 so is that 64kb?
    Also, I cannot see a battery that I recognise on the board. I have attached 2 pictures of my motherboard.
    IMG_20200630_120243.jpg
    IMG_20200630_120249.jpg

  5. #5
    Join Date
    Feb 2015
    Location
    Cleveland, OH, USA
    Posts
    1,214

    Default

    Quote Originally Posted by Sue Zuki View Post
    I recently acquired my first vintage PC as the above title. It has no video card. I searched the forum but to be honest I'm not really sure what I'm looking for!

    The mainboard is an Intel PSBC386AT25C04, if that helps. I have found some RAM for it. Can you also tell me what type of monitor I will need?

    Thanks for looking.
    Congratulations on your acquisition.

    I apologize for my ignorance about the 80386 AT&T; I have never seen one. But I do have the AT&T 8086 and 80286 machines, and from the looks of things they are quite similar. To answer a few of your questions:

    The 6300 had a dedicated video card that plugged into the backplane, and was normally used with one of the AT&T monitors, either monochrome (green) or color. The machine also could be used with a third-party video card, and I assume the same is true for yours. A VGA card designed for an ISA bus slot will fill your requirements, but I think you need to locate some documentation for your machine as you probably will need to change a jumper or a BIOS setting to enable use of the third-party card.

    As for a monitor, almost any VGA-capable monitor will do. You can even attach a later LED monitor in lieu of the CRT monitors of the day.

    RAM is not "fungible", alas, so again you will want to find the specs for that machine. I mean by that you can't plug just any old chip in there and get results: refresh rates, access cycles, capacities, voltages and pin assignments all make a difference.

    One clever design feature of the AT&T (Olivetti) motherboards: They put the clock battery on the underside of the motherboard, so when it leaked corrosive electrolyte - they all do eventually - it would drip harmlessly on the bottom of the case rather than on the delicate electronic pathways. Many a board has been ruined by that design oversight.

    There are a number of AT&T experts here on this site and I'm sure all will be willing to help further your knowledge. Good luck and happy twiddling.

    -CH-

  6. #6
    Join Date
    Aug 2015
    Location
    Kansas City area, US
    Posts
    66

    Default

    I'm pretty sure the MCM chips are static ram for cache. The ram looks to be 30-pin simms, those white sockets in the bottom left of your first picture. With a 32-bit 386dx, you probably need them in sets of 4. Looks like it has a Dallas Semi Timekeeper module in the upper left hand corner of your first picture. Unfortunately those tend to have a non (easily) servicable battery integrated within the package. Might look around for a four pin header in the vicinity though.

  7. #7

    Default

    Thanks for your comments, Iíll have a scout around for more info on it. I have purchases a vga card and just waiting for it to arrive from Estonia. I had a couple of ram modules that I put into the slots but I have no idea if it will work. Iíll let you know once the card comes.

  8. #8

    Default

    There is indeed a Dallas DS1287 on the mainboard. I have no idea if it has any charge until I try to boot the machine. Good news is that Mouser sell them for just under £10 with the suffix 12887. Thanks for the heads up eswan.

    What would I be looking for a 4 pin header for?

  9. #9
    Join Date
    Aug 2015
    Location
    Kansas City area, US
    Posts
    66

    Default

    Sometimes there will be a 4 pin header for an external clock battery. Looks identical to a speaker connector though.

  10. #10

    Default

    That motherboard is the Intel 303 AFAIK. I think it can take 256K or 1MB simms. Jumpers have to be set on the motherboard. Here is all the info i have on that motherboard:

    http://66.113.161.23/~mR_Slug/device...ual/index.html

    I'm sorry it is a bit disorganized but it is converted from a windows help (.hlp) file and that is the order the information it was in. If you search the page for "Memory Options" you will find the jumper settings you need. I would say you most likely currently have 4MB RAM installed. If you want to add 4 more 1MB modules to bring it up to 8MB RAM you will need to put a jumper between pins E7 to E9.

    Memory config on this board is complicated. The long slots you have are something called the AT32 bus. It is mainly used for memory expansion. The board has to know where the memory is located, on the board or memory expansion card, hence the need for jumpers.

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
  •