1 1 1 1 1 2 2 2 2 2 3 3 3 3
2 4 6 8 0 2 4 6 8 0 2 4 6 8 0 2 4 6
- - - - - - - - - - - - - - - - - -
- - - - - - - - - - - - - - - - - -
1 3 5 7 9 1 1 1 1 1 2 2 2 2 2 3 3 3
1 3 5 7 9 1 3 5 7 9 1 3 5
R D D D D D D D D
e 7 6 5 4 3 2 1 0
s
e
t
Pin# 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 <> Data bus .
6 CRUIN < CRU input to TMS9900 .
7 D5 <> Data bus .
8 A15 > Address bus, bit 15 / also CRU output bit .
9 D4 <> Data bus .
10 A13 > Address bus .
11 D3 <> Data bus .
12 A12 > Address bus .
13 D2 <> Data bus .
14 A11 > Address bus .
15 D1 <> Data bus .
16 A10 > Adresss bus .
17 D0 <> Data bus, bit 0 (most significant) .
18 A9 > Address bus .
19 VCC +5 Volts power supply .
20 A8 > Address bus .
21 GS* > Grom select. Active low is addr in >9800-9FFF .
22 A7 > Address bus .
23 A14 > Address bus, bit 14. Select mode: low=data / high=addr .
24 A3 > Address bus .
25 DBIN > Active high = read memory .
26 A6 > Address bus .
27 GRC > GROM clock: color burst of VDP 9918A .
28 A5 > Address bus .
29 VDD -5 Volts power supply .
30 A4 > Address bus .
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 Ground .
36 GND Ground .