Amstrad 40030 PAL (PAL16L8) pinout
DIP-20. 128K RAM banking: second-bank /CAS and the A14/A15 remap for the 6128 RAM configurations
Holds the 6128 RAM configuration register: an OUT to &7Fxx with D7 and D6 both HIGH latches D0-D2. It then steers /CAS to bank 0 (IC127-134) or bank 1 (IC119-126) and rewrites A14/A15 for the multiplexers, so a block of the second 64K appears at &4000 or elsewhere. Without it (64K builds) links LK5, LK6 and LK8 are closed. A bad PAL gives a 6128 that works in BASIC but fails CP/M Plus or |BANK commands.
Open the interactive 40030 pinoutPins
| Pin | Name | Type | Signal |
|---|---|---|---|
| 1 | D7·D6 | ctrl | D7 AND D6 from a 74LS08 gate: HIGH marks a RAM-configuration write. |
| 2 | D0 | data | RAM configuration bit 0. |
| 3 | /RESET | ctrl | Reset clears the configuration to 0 (normal 64K map). |
| 4 | RAMDIS | ctrl | Expansion RAMDIS: HIGH turns both banks off. |
| 5 | D1 | data | RAM configuration bit 1. |
| 6 | D2 | data | RAM configuration bit 2. |
| 7 | /CAS | ctrl | /CAS from Gate Array pin 16 (NCAS). |
| 8 | A15 | addr | CPU address bit 15. |
| 9 | A14 | addr | CPU address bit 14. |
| 10 | GND | ground | 0 V. |
| 11 | /CPU | ctrl | Gate Array /CPU phase: remap only during CPU accesses, never for video. |
| 12 | A15OUT | addr | Remapped A15 to the 74LS153 multiplexer (IC109). |
| 13 | NC | nc | Unused output (signals present, not connected). |
| 14 | NC | nc | Unused output. |
| 15 | NC | nc | Unused output. |
| 16 | /CAS1 | ctrl | CAS for bank 1, the second 64K (IC119-126), through R160, 47 ohms. |
| 17 | /CAS0 | ctrl | CAS for bank 0, the first 64K (IC127-134), through R161, 47 ohms. |
| 18 | /IOWR | ctrl | I/O write strobe (from the 74LS32): latches the configuration. |
| 19 | A14OUT | addr | Remapped A14 to the 74LS153 multiplexer. |
| 20 | VCC | power | +5 V. |
Fitted in
- Amstrad CPC 6128 IC118 (socket J106)