8 PIN DIN ‘C’ FEMALE at the Monitor
The Commodore 1084 and 1084S colour monitors, introduced in 1986–1988, accept digital TTL RGBI video through an 8-pin DIN ‘C’ female socket on the rear panel. This input is electrically compatible with IBM CGA-level TTL RGB signals and was primarily intended for use with the Commodore 128’s 80-column RGBI output and other home computers of the era. The same physical monitor also provides a separate 6-pin DIN socket for analogue RGB; only one input is active at a time. The later 1084D and 1084DS variants replaced both DIN sockets with a single 9-pin D-Sub connector.
| Pin | Name | Description |
|---|---|---|
| 1 | n/c | Not connected |
| 2 | R | Red |
| 3 | G | Green |
| 4 | B | Blue |
| 5 | I | Intensity |
| 6 | GND | Ground |
| 7 | HSYNC | Horizontal Sync |
| 8 | VSYNC | Vertical Sync |
Signals
- n/c — Pin 1 is not connected on the 1084/1084S. Note: an alternative pinout found in some secondary sources assigns Red to pin 1 and leaves pin 8 as NC; the assignment above (pin 1 = NC, pin 2 = Red) matches the Commodore 1084S Color Monitor Manual and is consistent with the allpinouts table.
- R — Digital red channel; TTL logic level.
- G — Digital green channel; TTL logic level.
- B — Digital blue channel; TTL logic level.
- I — Intensity bit, controlling the high/low brightness of all three colour channels simultaneously (RGBI model); equivalent to the IBM CGA intensity signal.
- GND — Signal ground reference.
- HSYNC — Horizontal synchronisation pulse.
- VSYNC — Vertical synchronisation pulse.
Notes
- The 8-pin DIN ‘C’ connector on the monitor is female; the mating plug on the computer cable is male.
- Input signals are TTL-level digital (0 V / 5 V logic); do not connect analogue RGB signals to this port.
- The 1084S monitors display 15 kHz horizontal scan rate (line frequency 15734 Hz, field rate 60 Hz); only sources operating at this scan rate are compatible.
- The 1084D and 1084DS variants omit both DIN sockets and instead use a single DE-9 (9-pin D-Sub) female connector that supports analogue and digital modes via a switch or automatic detection.
References
- Commodore 1084S Color Monitor Manual (1988) — Commodore Business Machines
- Commodore 1084S Monitor Manual — Technical Specifications (ManualsLib) — Commodore Business Machines