https://web.archive.org/web/20141129194124/http://support.radioshack.com/productinfo/DocumentResults.asp?sku_id=25-1454&Name=Tandy Desktops&Reuse=N <shrug>
Mike
Info should be on the Wayback Machine: https://web.archive.org/web/20141129194123/http://support.radioshack.com/productinfo/DocumentResults.asp?sku_id=25-1623&Name=Tandy Desktops&Reuse=N
Mike
Contact Ian Mavric. Knowledgeable, fast, reliable, highly rcommended, sadely (apparently) no longer on this site. http://members.iinet.net.au/~ianmav/trs80/
Mike
In case you don't have the link: https://web.archive.org/web/20141129194134/http://support.radioshack.com/productinfo/DocumentResults.asp?sku_id=25-4002&Name=Tandy%20Desktops&Reuse=N
Mike
Frank:
https://web.archive.org/web/20141129194126/http://support.radioshack.com/productinfo/DocumentResults.asp?sku_id=25-4072&Name=Tandy%20Desktops&Reuse=N "Memory Upgrades" gives some info on the memory board.
Mike