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IBM EGA Card Memory Expansion Boards

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    #16
    Good news and bad news...

    So the good news is... It works. I soldered it together and it required zero rework. Always nice when that happens.
    The bad news is there's some fitment issues. The holes for the standoffs had to be drilled out a bit... Not sure yet if that was a design problem or if I just hit the maximum size the board house can drill. Also I think I need a longer pin header to connect to the EGA card, because I have to bend the board in order to plug it in completely if using the standoffs.

    Overall not too bad for a prototype!
    Attached Files

    Comment


      #17
      Nice job on the board!

      Comment


        #18
        outstanding!

        Comment


          #19
          You might be able to just use a M-F header to extend the pins and get the proper board spacing.

          Comment


            #20
            Originally posted by mikey99 View Post
            You might be able to just use a M-F header to extend the pins and get the proper board spacing.
            Good thinking. Though that may add too much length, really only need another 4mm or so

            Comment


              #21
              Good job, I suppose that many geeks here welcome this replacement when it will be for good price.
              IBM PC 5150(A): IBM PC 5150(B): IBM PC 5160 (64-256k): IBM PC 5160 (256-640k): IBM PC 5170 (099): IBM PC 5170 (319/339): IBM PC 5140: IBM PC 5162: IBM PC 5155: IBM PC Expansion Unit 5161:
              WANTED!: IBM 5175 monitor, IBM 5145 monitor, IBM PC/XT/AT rear screws, Intel INBOARD 386AT card, IBM 5140 keyboard, very early IBM PC (S/N: under 5000)
              My IBM PC hardware collection

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                #22
                Has anyone found a reasonable price on the (24) 4416 memory chips needed for this board ?

                I've always wondered if it would be possible to modify the card slightly to use
                fewer and cheaper memory chips (ex one bank of 256K chips)

                I think it depends on how the memory is configured on the card, just seen as
                192K or does the card access each bank separately.

                Comment


                  #23
                  Originally posted by mikey99 View Post
                  Has anyone found a reasonable price on the (24) 4416 memory chips needed for this board ?
                  There is a compatibility table at the bottom of [here].

                  You could win eBay auction 392596996728 really cheaply. 400 pieces of M5M4416P-15. Current bid: US $3.99. Put aside 24 plus some spares, then use the remainder as Christmas tree decorations (although, probably more appropriate as b-tree decorations).

                  eBay item 174023679712 (buy-it-now) is for 40 pieces of MB81416. That corresponds to about 50 US cents (plus postage) for each chip, and includes enough spares to last you until the death of the planet due of climate change.

                  Comment


                    #24
                    Thanks modem7 ! Your eBay search skills are better than mine
                    Picked up one of the 40 chip lots, that's a great price.

                    Comment


                      #25
                      I would very much like to build one of these, are you willing to release the design files?

                      Comment


                        #26
                        I'd be very interested as well. Also curious how much it cost to have this printed, and what the cost of components were?

                        Comment


                          #27
                          IBM EGA 8-bit ISA Card with Memory Expansion Module 6480099 1501530XM

                          https://www.ebay.com/itm/283787270426?nordt=true

                          The Memory Expansion Card seems to be early type than IBM original EGA card.

                          I didn't bid it because I've already have IBM original EGA card (P/N:6278173XM).

                          Comment


                            #28
                            I already have an IBM EGA, paying $200+ on eBay is unacceptable

                            Comment


                              #29
                              I don't mind sharing the design files for this. You can download KiCad and Gerber files here
                              I'd recommend using the longest pin header you can find for the connector. The most expensive part of the build is the memory itself. I found a decent deal on UTSource, but some patience watching eBay auctions might work as well. The rest of the parts (sockets, capacitors, etc) total less than $20 from Mouser.

                              I do also have some spare PCBs due to the minimum order quantity from the board house. Maybe $5 plus shipping? I really just need to open an Etsy shop or something these days

                              Comment


                                #30
                                In preparation for this, I pulled out my IBM EGA and stuck it in my 5150. It works, but checkit is showing memory errors between 0A0000h and 0A001Eh. There appear to only be 8 memory ICs on the EGA, but I don't recognize the part numbers. Also do not know which one would correspond to this range. I've attached a photo. Any thoughts?

                                20200229_162902.jpg

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