The Apple Video Mirror connector is a 22-pin proprietary internal connector fitted to the Power Macintosh 5400 (1996), designed to support an optional add-in video buffer board that mirrors the internal display to an external monitor. It carries analogue RGB video signals, composite sync (CSYNC), separate horizontal and vertical sync lines, a dot clock scaled to 10 per cent, and multiple power rails (+5 V, +12 V, −12 V). Several pins — including audio left/right, I²C data and clock, and a sync-enable line — are populated on the connector but marked reserved and not used in the standard configuration.
| Pin | Name | Description |
|---|---|---|
| 1 | VID.GND | Video ground |
| 2 | RED | Red signal |
| 3 | GREEN | Green signal |
| 4 | VID.GND | Video ground |
| 5 | VID.GND | Video ground |
| 6 | BLUE | Blue signal |
| 7 | CSYNC | C sync |
| 8 | VSYNC | Vertical sync |
| 9 | MLB.SYNC.EN.L | Not used (reserved) |
| 10 | HSYNC | Horizontal sync |
| 11 | DAC.ISET.1 | Not used(reserved) |
| 12 | DAC.ISET.2 | Not used (reserved) |
| 13 | SND.GND | Not used (reserved) |
| 14 | SND.RIGHT | Not used (reserved) |
| 15 | SND.LEFT | Not used (reserved) |
| 16 | +5V | +5 volts |
| 17 | GND | Ground |
| 18 | SDAT | Not used (reserved) |
| 19 | SCLK | Not used (reserved) |
| 20 | +12V | +12 volts |
| 21 | -12V | -12 volts |
| 22 | Dot | Clock Scaled dot clock (scaled to 10 percent) |
Notes
- This is a 22-pin internal board-to-board connector, not an external port; an add-in video buffer card was required to make use of the mirror output on the Power Macintosh 5400.
- The dot clock on pin 22 is provided at 10 per cent of the normal pixel clock rate; external circuitry on the buffer board was responsible for reconstituting the full-rate clock.
- Pins 13–15 (SND.GND, SND.RIGHT, SND.LEFT) and pins 18–19 (SDAT, SCLK — I²C data and clock) are physically present but reserved and carry no signal in the standard implementation.
- Pin 9 (MLB.SYNC.EN.L) and pins 11–12 (DAC.ISET.1, DAC.ISET.2) are similarly reserved.
- Power rails: +5 V (pin 16), +12 V (pin 20), and −12 V (pin 21); ground is split between multiple video-ground pins (1, 4, 5) and a common ground (pin 17).
Signals
- VID.GND — Video signal ground reference (pins 1, 4, 5)
- RED — Analogue red video signal
- GREEN — Analogue green video signal
- BLUE — Analogue blue video signal
- CSYNC — Composite sync (combined horizontal and vertical sync)
- VSYNC — Vertical sync
- HSYNC — Horizontal sync
- MLB.SYNC.EN.L — Motherboard sync enable (active low); reserved, not connected in standard configuration
- DAC.ISET.1 — DAC current-set reference 1; reserved, not used
- DAC.ISET.2 — DAC current-set reference 2; reserved, not used
- SND.GND — Audio ground; reserved, not used
- SND.RIGHT — Audio right channel; reserved, not used
- SND.LEFT — Audio left channel; reserved, not used
- +5V — +5 volt power rail
- GND — Common ground
- SDAT — I²C serial data; reserved, not used
- SCLK — I²C serial clock; reserved, not used
- +12V — +12 volt power rail
- -12V — −12 volt power rail
- Dot — Dot clock output, scaled to 10 per cent of the normal pixel clock frequency
References
- Power Macintosh 5400 Developer Note — Apple Computer, Inc., 1996 (no accessible online URL; archived at preterhuman.net, currently 404)