Replacing 6550s

Hi all! Thanks to everyone who supplied information regarding the differences between the 6550 and 2114 (especially Ethan who supplied pinouts). I'm wondering if it would be possible to replace the RAM in an old PET with a modern SRAM by use of some kind of plug-in adapter. An example of what I'm thinking of is the SIMMfonie or AmiFast Zip-to-SIMM adapters for the Amiga 3000. Could something like this be built that would plug into the 16 22-pin sockets on the PET motherboard, and lead to a single modern SRAM? Possibly with the addition of a couple of clip-on leads to get two more address lines to the RAM adapter so that the PET could have 32K. My general preference is to keep things original, but functional is always better than non-functional and something like this adapter would be removable if I ever found the proper chips. The life of a chicklet-keyboard PET may depend on this. :) -- Doug Spence ds_spenc(a)alcor.concordia.ca http://alcor.concordia.ca/~ds_spenc/