Need Docs for XT RAM Board...

Al Hartman alhartman at
Wed Nov 8 21:45:59 CST 2006

I'll take a look. But I think all four rows are soldered in.


> If it's an IBM XT mainboard, there's an easy way to do this (and not use 
> up any expansion slots).
> Put 41256 chips in banks 0 and 1, and 4164s in banks 2 and 3 on the 
> mainboard. Put a 74S158 (or 74F158) multiplexer chip in the emptu socket 
> at the front right, pointing the same way as the chips around it. Set the 
> DIP switches for 256K RAM, and solder a jumper wire between pads E1 and E2.
> That's it. You have a 640K XT mainboard.
> -tony

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