The Amiga video expansion slot is an internal 90-pin edge connector (36 pins on one side, 54 on the other) found in the Commodore Amiga 2000 and Amiga 3000. It was introduced alongside the A2000 in 1987 and is documented in the Commodore Amiga A500–A2000 Technical Reference Manual and the Amiga Hardware Reference Manual (3rd edition, 1991). The slot provides all the signals present on the external 23-pin DB23 video port plus unencoded 12-bit digital RGB video (RGB0–RGB23), genlock signals, pixel clock, colorburst, audio, and power rails, giving expansion cards direct access to the unprocessed video data stream. It was used by devices such as the NewTek Video Toaster, the Commodore A2320 flicker fixer, and various third-party genlock and frame-grabber cards.
36+54 PIN EDGE CONNECTOR at the computer
| Pin | Name | Dir | Description |
|---|---|---|---|
| 1 | RGB16 | OUT | Red Bit 0 |
| 2 | RGB17 | OUT | Red Bit 1 |
| 3 | LINELF | OUT | Audio Line Out Left |
| 4 | LINERT | OUT | Audio Line Out Right |
| 5 | C28D | OUT | Pixel-Synchronous Clock |
| 6 | +5V | - | +5 Volts DC (1 A) |
| 7 | ARED | OUT | Analog Red |
| 8 | +5V | - | +5 Volts DC (1 A) |
| 9 | GND | - | Digital Ground |
| 10 | +12V | - | +12 Volts DC (40 mA) |
| 11 | AGREEN | OUT | Analog Green |
| 12 | GND | - | Digital Ground |
| 13 | GND | - | Digital Ground |
| 14 | /CSYNC | OUT | Composite Sync |
| 15 | ABLUE | OUT | Analog Blue |
| 16 | /XCLKEN | IN | Genlock Clock Enable |
| 17 | GND | - | Digital Ground |
| 18 | BURST | OUT | Burst Gate |
| 19 | /C4 | OUT | 3.55/3.58 MHz Clock |
| 20 | GND | - | Digital Ground |
| 21 | GND | - | Digital Ground |
| 22 | /HSYNC | OUT | Horizontal Sync (47 Ohm) |
| 23 | RGB4 | OUT | Blue Bit 4 |
| 24 | GND | - | Digital Ground |
| 25 | RGB7 | OUT | Blue Bit 7 |
| 26 | /VSYNC | OUT | Vertical Sync (47 Ohm) |
| 27 | RGB15 | OUT | Green Bit 7 |
| 28 | BLANK | OUT | Video Blank |
| 29 | RGB23 | OUT | Red 7 |
| 30 | /PIXELSW | OUT | Genlock Overlay (47 Ohm) |
| 31 | -5V | - | -5 Volts DC |
| 32 | GND | - | Digital Ground |
| 33 | /XCLK | IN | Genlock Clock |
| 34 | /C1 | OUT | C1 Clock |
| 35 | +5V | - | +5 Volts DC (1 A) |
| 36 | PSTROBE | OUT | Printer Port Handshake |
| 1 | GND | - | Digital Ground |
| 2 | RGB20 | OUT | Red Bit 4 |
| 3 | RGB21 | OUT | Red Bit 5 |
| 4 | RGB22 | OUT | Red Bit 6 |
| 5 | GND | - | Digital Ground |
| 6 | RGB12 | OUT | Green Bit 4 |
| 7 | RGB13 | OUT | Green Bit 5 |
| 8 | RGB14 | OUT | Green Bit 6 |
| 9 | GND | - | Digital Ground |
| 10 | RGB5 | OUT | Blue Bit 5 |
| 11 | RGB6 | OUT | Blue Bit 6 |
| 12 | GND | - | Ground |
| 13 | SOG | OUT | Sync-On-Green Indicator |
| 14 | TBASE | OUT | 50/60 Hz Software Clock Timebase |
| 15 | CDAC | OUT | 7.09/7.16 MHz Clock |
| 16 | PPOUT | IN/OUT | Printer Port Paper Out |
| 17 | /C3 | OUT | 3.55/3.58 MHz Clock |
| 18 | PBUSY | IN/OUT | Printer Port Busy |
| 19 | /LPEN | IN | Light Pen Input |
| 20 | /PACK | IN/OUT | Printer Port Acknowledge Handshake |
| 21 | PSEL | OUT | Printer Port Select |
| 22 | GND | - | Digital Ground |
| 23 | PPD0 | IN/OUT | Printer Port Data Bit 0 |
| 24 | PPD1 | IN/OUT | Printer Port Data Bit 1 |
| 25 | PPD2 | IN/OUT | Printer Port Data Bit 2 |
| 26 | PPD3 | IN/OUT | Printer Port Data Bit 3 |
| 27 | PPD4 | IN/OUT | Printer Port Data Bit 4 |
| 28 | PPD5 | IN/OUT | Printer Port Data Bit 5 |
| 29 | PPD6 | IN/OUT | Printer Port Data Bit 6 |
| 30 | PPD7 | IN/OUT | Printer Port Data Bit 7 |
| 31 | /LED | OUT | LED (Audio filter bypass) Setting |
| 32 | GND | - | Digital Ground |
| 33 | RAWLF | OUT | Raw (Unfiltered) Audio Left |
| 34 | AGND | - | Audio Ground |
| 35 | RAWRT | OUT | Raw (Unfiltered) Audio Right |
| 36 | AGND | - | Audio Ground |
| 37 | n/c | - | Reserved for future expansion |
| 38 | n/c | - | Reserved for future expansion |
| 39 | GND | - | Digital Ground |
| 40 | GND | - | Digital Ground |
| 41 | n/c | - | Reserved for future expansion |
| 42 | n/c | - | Reserved for future expansion |
| 43 | GND | - | Digital Ground |
| 44 | GND | - | Digital Ground |
| 45 | RGB18 | OUT | Red Bit 2 |
| 46 | RGB19 | OUT | Red Bit 3 |
| 47 | RGB8 | OUT | Green Bit 0 |
| 48 | RGB9 | OUT | Green Bit 1 |
| 49 | RGB10 | OUT | Green Bit 2 |
| 50 | RGB11 | OUT | Green Bit 3 |
| 51 | RGB0 | OUT | Blue Bit 0 |
| 52 | RGB1 | OUT | Blue Bit 1 |
| 53 | RGB2 | OUT | Blue Bit 2 |
| 54 | RGB3 | OUT | Blue Bit 3 |
Notes
- Direction is motherboard relative to card.
- The connector is a dual-row PCB edge connector; the first section (pins 1–36) occupies one side and the second section (pins 1–54) the other.
- Do not mix analogue and digital grounds; separate AGND pins are provided for audio circuits.
- All logic signals are 5 V TTL-compatible. Analogue video outputs (ARED, AGREEN, ABLUE) are driven by the Amiga’s DAC and must not be loaded beyond the rated impedance.
- /HSYNC and /VSYNC are driven through 47 Ω series resistors on the motherboard; /PIXELSW likewise.
- The genlock inputs /XCLK and /XCLKEN allow an external genlock card to inject a replacement colour-burst clock, locking the Amiga’s video output to an external video source.
Signals
- RGB0–RGB3 — Blue channel, bits 0–3 (unencoded digital video, 4-bit blue LSBs)
- RGB4–RGB7 — Blue channel, bits 4–7 (unencoded digital video, 4-bit blue MSBs)
- RGB8–RGB11 — Green channel, bits 0–3 (unencoded digital video, 4-bit green LSBs)
- RGB12–RGB15 — Green channel, bits 4–7 (unencoded digital video, 4-bit green MSBs)
- RGB16–RGB19 — Red channel, bits 0–3 (unencoded digital video, 4-bit red LSBs)
- RGB20–RGB23 — Red channel, bits 4–7 (unencoded digital video, 4-bit red MSBs)
- ARED / AGREEN / ABLUE — Analogue RGB video outputs, same signals as the external DB23 video port
- /CSYNC — Composite sync output
- /HSYNC — Horizontal sync output (driven through 47 Ω)
- /VSYNC — Vertical sync output (driven through 47 Ω)
- BLANK — Video blanking signal; asserted during horizontal and vertical blanking intervals
- SOG — Sync-on-green indicator
- BURST — Colour-burst gate signal used by genlock cards to lock to the subcarrier phase
- /PIXELSW — Genlock overlay / pixel switch; asserted by a genlock card to substitute external video for Amiga video (driven through 47 Ω)
- /XCLK — Genlock clock input; external clock supplied by a genlock card to replace the internal colour-burst reference
- /XCLKEN — Genlock clock enable input; enables the external clock on /XCLK
- C28D — Pixel-synchronous clock output (28 MHz dot clock)
- /C1 — C1 clock output (approximately 3.55/3.58 MHz, 90° phase)
- /C3 — C3 clock output (approximately 3.55/3.58 MHz, 270° phase)
- /C4 — Colour-burst clock output (approximately 3.55/3.58 MHz)
- CDAC — 7.09/7.16 MHz clock output (colour-clock × 2)
- TBASE — 50/60 Hz software clock timebase output
- LINELF / LINERT — Audio line output, left and right channels (filtered)
- RAWLF / RAWRT — Raw (unfiltered) audio output, left and right channels; bypasses the Amiga’s audio low-pass filter
- AGND — Audio ground (separate from digital GND to reduce noise coupling)
- /LPEN — Light-pen input; connects to the Agnus chip’s light-pen latch
- PSTROBE / PPOUT / PBUSY / /PACK / PSEL / PPD0–PPD7 — Parallel printer port signals (Centronics-compatible handshake and data lines) mirrored from the external printer port
- /LED — LED / audio-filter bypass control; setting this line low bypasses the audio low-pass filter
- +5V — +5 V DC supply rail (1 A total across all +5 V pins)
- +12V — +12 V DC supply rail (40 mA)
- -5V — −5 V DC supply rail
- GND — Digital ground
- n/c — Not connected; reserved for future expansion