Can the psx use a pin per pin matching parallel flash ic on the address and data lines on the pio port, with ce rd wr too? Also meaning not using a gal logic chip like in the xploder carts. Does the psx auto map the new chip and would be able to boot unirom forexample?
http://i.imgur.com/wb8UoAy.jpg
Sorta like a xploder concept. with a host pc app.
512KB external bios
512KB external pio rom
ATmega1284p MCU
2x MCP2221
PIC16F629
74HC245 Latch