TI-99/4A Cartridge Port

From HwB

Available at Texas Instruments TI-99/4A computers.

Pinout

On the top

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

Contributions