Subversion Repositories Shiroi

I/O List

If the I/O port (3n-1) returns 0, card is not there.

I/O port (3n-1) returns the card type.
        Top 4 bits mean the card genre:
                0x0: Video
                0x1: Audio
                0x2: System
        Bottom 4 bits mean the card type:
                Video:
                        0x1: Video Mark I
                        0x2: Video Mark II
                Audio:
                        0x1: Sound Mark I
                System:
                        0x1: Math Mark I
                        0x2: Text Mark I
                        0x3: Debug

Video Mark I card maps itself to:
        0: VDP address
        1: VDP data
        2: See above

Video Mark II card maps itself to:
        0: VDG VRAM address
        1: VDG VRAM data
        2: See above

Sound Mark I card maps itself to:
        3: PSG address
        4: PSG data
        5: See above

Math Mark I card maps itself to:
        6: AM9511 stack
        7: AM9511 command (W) / AM9511 ready (R)
        8: See above

Text Mark I card maps itself to:
        9: Keyboard data
        10: Empty
        11: See above

Debug card maps itself to:
        12: Address
        13: LED
                Bit to 7-segment map:
                 0
                1 2
                 3
                4 5
                 6 7
        14: See above