Cartrige Port Pinouts

# Name I/O Use
- ---- --- -----------
1 RESET < Resets the system (active high)
2 GND Signal groud
3 D7 <> Data bus, bit 7 (least significant)
4 CRUCLK* > Inversion of TMS9900 CRUCLOCK pin
5 D6 <>
6 CRUIN < CRU input to TMS9900
7 D5 <>
8 A15 > Address bus, bit 15 / also CRU output bit
9 D4 <>
10 A13 >
11 D3 <>
12 A12 >
13 D2 <>
14 A11 >
15 D1 <>
16 A10 >
17 D0 <> Data bus, bit 0 (most significant)
18 A9 >
19 VCC +5 Volts power supply
20 A8 >
21 GS* > Grom select. Active low is addr in >9800-9FFF
22 A7 >
23 A14 > Address bus, bit 14. Select mode: low=data / high=addr
24 A3 >
25 DBIN > Active high = read memory
26 A6 >
27 GRC > GROM clock: color burst of VDP 9918A
28 A5 >
29 VDD -5 Volts power supply
30 A4 >
31 GR < Active high = GROM ready
32 WE* > Active low = write enable (derived from TMS9900 WE*)
33 VSS
34 ROMG* > Active low if addr in >6000-7FFF
35 GND
36 GND