Available at the Commodore 128.
44 PIN FEMALE EDGE at the computer.
| Pin | Name | Description |
| 1 | GND | System Ground |
| 2 | +5V | System Vcc |
| 3 | +5V | System Vcc |
| 4 | /IRQ | Interrupt request |
| 5 | R/W | System Read/Write Signal |
| 6 | DClock | 8.18MHz Video Dot Clock |
| 7 | I/O1 | I/O Chip select $de00-deff |
| 8 | /GAME | Sensed for memory map configuration |
| 9 | /EXROM | Sensed for memory map configuration |
| 10 | I/O2 | I/O Chip select $df00-dfff |
| 11 | /ROML | External ROM select $8000-Bfff |
| 12 | BA | Bus available output |
| 13 | /DMA | Direct memory access input |
| 14 | D7 | Data bit 7 |
| 15 | D6 | Data bit 6 |
| 16 | D5 | Data bit 5 |
| 17 | D4 | Data bit 4 |
| 18 | D3 | Data bit 3 |
| 19 | D2 | Data bit 2 |
| 20 | D1 | Data bit 1 |
| 21 | D0 | Data bit 0 |
| 22 | GND | System Ground |
| | | |
| A | GND | System Ground |
| B | /ROMH | External ROM Select $c000-ffff |
| C | /RESET | System Reset Signal |
| D | /NMI | Non-Maskable Interrupt |
| E | 1MHz | System 1MHz clock |
| F | TA15 | Translated address bit 15 |
| H | TA14 | Translated address bit 14 |
| J | TA13 | Translated address bit 13 |
| K | TA12 | Translated address bit 12 |
| L | TA11 | Translated address bit 11 |
| M | TA10 | Translated address bit 10 |
| N | TA9 | Translated address bit 9 |
| P | TA8 | Translated address bit 8 |
| R | SA7 | Shared address bit 7 |
| S | SA6 | Shared address bit 6 |
| T | SA5 | Shared address bit 5 |
| U | SA4 | Shared address bit 4 |
| V | SA3 | Shared address bit 3 |
| W | SA2 | Shared address bit 2 |
| X | SA1 | Shared address bit 1 |
| Y | SA0 | Shared address bit 0 |
| Z | GND | System Ground |