Atari 8-Bit Computer

Peripheral (SIO) Port

Pin	Description
1	Clock Input
2	Clock Output
3	Data Input
4	Ground
5	Data Output
6	Ground
7	Command
8	Motor Control
9	Proceed
10	+5V/Ready Disabled on 1200XL. Replace R63 with wire jumper to enable.
11	Audio Input
12	+12V on 400 and 800 only. Not connected on XL and XE.
13	Interrupt