IDE64 SHORT BUS --------------- rev. 17/03/2000 --------------------------------------------------------------------- | 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 | | o o o o o o o o o o o o o o o o o | | o o o o o o o o o o o o o o o o o | | 1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 | --------------------------------------------------------------------- Description of new C64 IDE V2.5 IO bus called SHORT BUS. Pin No. Name Description =============================================================================== 1 GND Ground 2 Vcc +5V 3 /Reset Reset signal, active low 4 CSEL4 Chip select signal, active high when CPU R/W $DE58,$DE59 5 R/W Read/Write signal from processor 6 /CSEL3 Chip select signal, active low when CPU R/W $DE48-$DE57 7 FI2 Fi2 clock signal from processor 8 /CSEL2 Chip select signal, active low when CPU R/W $DE38-$DE47 9 BA Bus Available, control signal from VIC 10 /CSEL1 Chip select signal, active low when CPU R/W $DE10-$DE1F 11 DOT clock Clock signal from VIC 12 /CSEL0 Chip select signal, active low when CPU R/W $DE00-$DE0F 13 /NMI Non maskable interrupt, active low 14 /IO2 Chip select signal, active low 15 /IRQ IRQ, active low 16 /IO1 Chip select signal, active low 17 D7 Data bus bit 7 18 A7 Adress bus bit 7 19 D6 Data bus bit 6 20 A6 Adress bus bit 6 21 D5 Data bus bit 5 22 A5 Adress bus bit 5 23 D4 Data bus bit 4 24 A4 Adress bus bit 4 25 D3 Data bus bit 3 26 A3 Adress bus bit 3 27 D2 Data bus bit 2 28 A2 Adress bus bit 2 29 D1 Data bus bit 1 30 A1 Adress bus bit 1 31 D0 Data bus bit 0 32 A0 Adress bus bit 0 33 Vcc +5V 34 GND Ground