Spectrum +3.
http://www.worldofspectrum.org/faq/reference/pinouts.htmRGB Pin Signal Level
-------------------------------------------------
1 +12V
2 GND 0V
3 Audio Out
4 /Composite Sync TTL
5 +12V
6 Green Analogue 1.67V p-p
7 Red Analogue 1.67V p-p
8 Blue Analogue 1.67V p-p
Amiga Video port.
1 /XCLK IN Extern Clock
2 /XCLKEN IN Extern Clock Enable (47 Ohm)
3 RED OUT Analog Red (75 Ohm)
4 GREEN OUT Analog Green (75 Ohm)
5 BLUE OUT Analog Blue (75 Ohm)
6 DI OUT Digital Intensity (47 Ohm)
7 DR OUT Digital Red (47 Ohm)
8 DG OUT Digital Green (47 Ohm)
9 DB OUT Digital Blue (47 Ohm)
10 /CSYNC OUT Composite Sync (47 Ohm)
11 /HSYNC OUT Horizontal Sync (47 Ohm)
12 /VSYNC OUT Vertical Sync (47 Ohm)
13 GNDRTN ------ Digital Ground (for /XCLKEN) Don't connect with pin 16-20.
14 /PIXELSW OUT Genlock overlay (47 Ohm)
15 /C1 OUT Clock out (47 Ohm)
16 GND ------ Video Ground
17 GND ------ Video Ground
18 GND ------ Video Ground
19 GND ------ Video Ground
20 GND ------ Video Ground
21 -12V OUT -12 Volts DC (10 mA max) (A500/A600/A1200)
-5V OUT -5 Volts DC (10 mA max) (A1000/A2000/A3000/A4000)
22 +12V OUT +12 Volts DC (100 mA max)
23 +5V OUT +5 Volts DC (100 mA max)