60 PIN EDGE CONNECTOR (.156") at the computer.
The Amiga 1000 RAMEX (RAM Expansion) connector is a 60-pin dual-row edge connector with 0.156-inch (3.96 mm) pitch, located on the front panel of the Commodore Amiga 1000 and used exclusively for chip RAM expansion. Unlike the 86-pin side expansion port found on the A1000 and A500, the RAMEX carries only the memory bus signals needed to address and transfer data to additional DRAM chips — it is not a general-purpose expansion bus. Commodore defined the connector in Appendix E of the Amiga Hardware Reference Manual; no later Amiga model (A500, A2000, A1200, or CD32) includes a RAMEX connector, making it unique to the original A1000.
| Pin | Name | Description |
|---|---|---|
| 1 | GND | Ground |
| 2 | D15 | Data 15 |
| 3 | +5V | +5 Volts DC |
| 4 | D12 | Data 12 |
| 5 | GND | Ground |
| 6 | D11 | Data 11 |
| 7 | +5V | +5 Volts DC |
| 8 | D8 | Data 8 |
| 9 | GND | Ground |
| 10 | D7 | Data 7 |
| 11 | +5V | +5 Volts DC |
| 12 | D4 | Data 4 |
| 13 | GND | Ground |
| 14 | D3 | Data 3 |
| 15 | +5V | +5 Volts DC |
| 16 | D0 | Data 0 |
| 17 | GND | Ground |
| 18 | DRA4 | |
| 19 | DRA5 | |
| 20 | DRA6 | |
| 21 | DRA7 | |
| 22 | GND | Ground |
| 23 | /RAS | |
| 24 | GND | Ground |
| 25 | GND | Ground |
| 26 | /CASU0 | |
| 27 | GND | Ground |
| 28 | /CASL0 | |
| 29 | +5V | +5 Volts DC |
| 30 | +5V | +5 Volts DC |
| A | GND | Ground |
| B | D14 | Data 14 |
| C | +5V | +5 Volts DC |
| D | D13 | Data 13 |
| E | GND | Ground |
| F | D10 | Data 10 |
| H | +5V | +5 Volts DC |
| J | D9 | Data 9 |
| K | GND | Ground |
| L | D6 | Data 6 |
| M | +5V | +5 Volts DC |
| N | D5 | Data 5 |
| P | GND | Ground |
| R | D2 | Data 2 |
| S | +5V | +5 Volts DC |
| T | D1 | Data 1 |
| U | GND | Ground |
| V | DRA3 | |
| W | DRA2 | |
| X | DRA1 | |
| Y | DRA0 | |
| Z | GND | Ground |
| AA | /RRW | |
| BB | GND | Ground |
| CC | GND | Ground |
| DD | /CASU1 | |
| EE | GND | Ground |
| FF | /CASL1 | |
| HH | +5V | +5 Volts DC |
| JJ | +5V | +5 Volts DC |
Signals
- D0–D15 — 16-bit bidirectional data bus; connects directly to the expansion DRAM chips for full-width memory access.
- DRA0–DRA7 — DRAM row address lines; multiplexed row address presented to the RAM chips during a row address strobe cycle.
- /RAS — Row Address Strobe (active low); latches the row address into the DRAM array.
- /RRW — RAM Read/Write (active low = write); controls the read or write direction of the DRAM access.
- /CASU0 — Column Address Strobe Upper byte, bank 0 (active low); latches the column address for the upper byte of the first bank.
- /CASL0 — Column Address Strobe Lower byte, bank 0 (active low); latches the column address for the lower byte of the first bank.
- /CASU1 — Column Address Strobe Upper byte, bank 1 (active low); latches the column address for the upper byte of the second bank.
- /CASL1 — Column Address Strobe Lower byte, bank 1 (active low); latches the column address for the lower byte of the second bank.
- +5V — +5 V DC power supply to the expansion RAM module.
- GND — Signal and power ground.
Notes
- The connector is a dual-row card edge type with 0.156-inch (3.96 mm) centre spacing — physically larger than the 0.1-inch pitch used on the A1000/A500 side expansion port.
- Pins on one side of the connector are numbered 1–30 (numeric); pins on the opposite side are lettered A–JJ, skipping the letters I, O, G, Q, and II to avoid confusion with numerals.
- The RAMEX port carries only the memory bus; it does not expose the full 68000 processor bus (no address lines A1–A23, no AS*, no interrupt or bus-arbitration signals). Expansion cards attached here cannot act as DMA masters or general peripherals.
- All signals are 5 V TTL-compatible; the power rails supply only enough current for DRAM expansion chips, not for additional logic-intensive peripherals.
- The RAMEX connector is unique to the Amiga 1000; the A500 and all subsequent Amiga models provide chip RAM expansion via other means (trapdoor slot, internal sockets, or the side expansion port) and do not include a RAMEX connector.
References
- Amiga Hardware Reference Manual, 2nd Edition — Commodore-Amiga Inc., 1989; Appendix E documents the A1000 RAMEX 60-pin connector pin assignments.
- Amiga Hardware Reference Manual, 3rd Edition — Commodore-Amiga Inc., 1991; Appendix E covers all Amiga I/O connectors including expansion ports.