;IOMAP
;0x40 INPUT read from ram expansion card (tbd)
;0x40 OUTPUT poke at FDC (tbd)
;0x48 INPUT read the key modifier bits (i assume) from keyboard, and the key pressed latch bit
;0x48 OUTPUT (unused in ROM) alternate poke at FDC
;0x50 INPUT read the keyboard state and clear they key ready latch
;0x50 OUTPUT tough to see from the schematic, seems to toggle an unconnected port, could be a feature we dont have?
;0x58 OUTPUT write to interface card register high
;0x60 OUTPUT write to interface card register low
;0x68 INPUT read from interface card buffer
;0x68 OUTPUT something to do with transmit (previously predicted this as transmit byte)
;0x70 INPUT read the interface card "printer status" register
;0x70 OUTPUT something to do with transmit (tbd)
;0x78 INPUT read the interface card status register
;0x78 OUTPUT write status to interface card