DB9 Connector

The DB9 connector is a 9-pin female, right-angled PCB-mount, sub-D connector.

DB9 connector
(PC bracket viewed from outside)

DB9 pins assignments

Pin location	Pin name	Usage
1	POWER	+5V power output or +12V power output
2	GND	Ground
3	VIDEO3/CHROMA	VIDEO Input 3 - Composite VIDEO Input 2 - CHROMA (C) component
4	GND	Ground
5	VIDEO2/LUMA	VIDEO Input 2 - Composite VIDEO Input 2 - LUMA (Y) component
6	IO1	General purpose IO 1
7	IO2	General purpose IO 2
8	IO3	General purpose IO 3
9	IO4	General purpose IO 4

VIDEO2 and VIDEO3 are selectable color or monochrome composite inputs. Each of them is terminated with a removable 75Ω resistor. The POWER pin can be connected to +5 V or +12 V.