Apricot Xi Memory and IO Card

Additional 640KB RAM, and IO breakout for prototyping.

Tested on PC/Xi, FP. Should be working on F2/F10. Not working on F1e with 128K RAM.

Schematics, PCB, Order from AISLER

Building and flashing GAL

make -C gal
minipro -p ATF16V8C --write gal/xi.jed -P

ToDo

• Loading caps on signal lines
• Move GAL to the left so it will be accessible without pulling the card
• Move testpoints to the bottom/make them THT, as it will make it more accessible from the case
• 3D-print a frame to hold the card in place
• DT/R̅ can be latched

Board verification

• GAL is compilable and flash-able
• pins 12, 19 can not be used as input in registered mode

Alternative options

• Apricot F Series expandable SRAM board by S.R.Usher