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HIMEMV2 or equivillent PROM

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Quote Originally Posted by ibmapc View Post
If your not familiar with the HIGHMEMV2, see the folowing Attachment 40433.It is a chip that replaces the rom in socket u44 on the IBM 5160 XT Motherboard to address memory up to 1 meg. I did the mod for 640KB on the motherboard about 25 years ago. So I have 256k chips in banks 0 and 1. I have enough 256k chips that I pulled from another board to fill the other two banks. I realize that the added memory will only give me about 64k of Contiguous base memory, but I believe there is a good size chunk of other unused memory between 640K and 1 Meg that could be used as UMB to load device drivers like Network drivers etc. using something like Quarterdeck Cram.
Chuck(G) had mentioned using a GAL to replace the rom, but I don't have the technical expertise to burn one properly. I'd be willing to pay for the chip plus shipping and any other costs incurred (within reason of coarse). I had also hi-jacked a thread in PC's AND CLONES that discussed this same topic, but that thread has gotten a little long and has not attracted much interest lately, so I decided a new thread here might get the right person or persons interested. Anyone willing to help me with this project, please PM me or E-mail me at
I know this is an old post from 2011. I just thought I'd post here a link to some files to make this mod a little easier. Attachment 40434 Attachment 40435

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