APPENDIX C: PINOUTS

D.I.N. 5 Monitor Jack (800 Only)

3       1
 5     4
    2

1. Composite Luminance
2. Ground
3. Audio Output
4. Composite Video
5. Composite Chroma

Atari FAQ says this is on "all but 400, N. American 600XL, XE Game System, SECAM systems"

Atari FAQ says composite chroma is "not on 800XL,1200XL; grounded on 600XL",
but on my late-model 800XL it certainly is, and has been used to drive S-video.

Serial I/O Jack (SIO) Port (all machines):

2           12
 o o o o o o
o o o o o o o
1            13

1. Clock Input             8. Motor Control
2. Clock Output            9. Proceed
3. Data Input             10. +5V/Ready (not on 1200XL)
4. Ground                 11. Audio Input
5. Data Output            12. +12V (400,800 only. 1400XL/1450XLD?)
6. Ground                 13. Interrupt
7. Command

Controller Jack (4 on 400/800, 2 on all others):

1   2   3   4   5
o   o   o   o   o
  o   o   o   o
  6   7   8   9

                                   CX22 trackball meanings from Steve Wallace:
1. (Joystick) Forward Input               X Direction
2. (Joystick) Back Input                  X Motion
3. (Joystick) Left Input                  Y Direction
4. (Joystick) Right Input                 Y Motion
5. B Potentiometer Input
6. Trigger Input / Light Pen Input. Port 4 only on 400
7. +5V
8. Ground
9. A Potentiometer Input