hex adr adr bus r/w data bus function E000-EFFF 111xAAAAAAAAAAAA R DDDDDDDD /ROM5 D000-DFFF 1101AAAAAAAAAAAA R DDDDDDDD /ROM4 C000-CFFF 1100AAAAAAAAAAAA R DDDDDDDD /ROM3 B000-BFFF 1011AAAAAAAAAAAA R DDDDDDDD /ROM2 A000-AFFF 1010AAAAAAAAAAAA R DDDDDDDD /ROM1 9000-9FFF 1001AAAAAAAAAAAA R DDDDDDDD /ROM0 8800 10001xxxxxxxxxxx R D CABINET 1 D /START2 D /START1 D /THRUST2 D /ROT LEFT 2 D /ROT RIGHT 2 D /FIRE 2 D /SHIELDS 2 89C0 1000100111xxxxxx W /SPARE WT 8980 1000100110xxxxxx W /WDCLR 8940 1000100101DDDDDD W DDDDDDDD /EAROMWR 8900 1000100100xxxxxx W DDDD /EAROMCON 88C0 1000100011xxxxxx W /INTACK 8880 1000100010xxxxxx W /VGRST 8840 1000100001xxxxxx W /VGGO 8800 10000xxxxxxxxxxx R D OPTION2 D OPTION1 D OPTION0 D /THRUST1 D /ROT LEFT 1 D /ROT RIGHT 1 D /FIRE 1 D /SHIELDS 1 7800 01111xxxxxxxxxxx R D 3KHZ D HALT D /SA D /SELF-TEST D /COIN-AUX D /COIN L D /COIN R 7000 01110xxxxxxxxxxx R DDDDDDDD /EAROMRD 6800 01101xxxxxxxxxxx R/W DDDDDDDD /I/O0 6000 01100xxxxxxxxxxx R/W DDDDDDDD /I/O1 5000-5FFF 0101AAAAAAAAAAAA R DDDDDDDD /VROM3 4000-4FFF 0100AAAAAAAAAAAA R DDDDDDDD /VROM2 3000-3FFF 0011AAAAAAAAAAAA R DDDDDDDD /VROM1 2800-2FFF 00101AAAAAAAAAAA R DDDDDDDD /VROM0 2000-27FF 00100AAAAAAAAAAA R/W DDDDDDDD /VRAM 0000-07FF 00000AAAAAAAAAAA R/W DDDDDDDD /RAM