http://neil.franklin.ch/Projects/Parport/Atari_Joystick
author Neil Franklin, last modification 2007.10.30


Connect an Atari VCS (Atari 2600) compatible DE9 connector Joystick (such as an
Kempston Competition Pro) to 5 pins of the PC parallel port (Parport),
(miss-)using it as an general purpose PIO port. These are the 2 wiring schemes
that are implemented in the Linux "Multisystem" (db9) Joystick driver, and may
be considered standard.

The "old" layout used the status port (5 input pins) and so worked on all PCs
(including all 1980s), but is limited to 1 fire button.

The "new" layout can provide up to 4 fire buttons for extended joysticks (often
(miss-)using the 3 Paddle pins), but requires an EPP style (can be switched to
input) data port (8 output/input pins). This is present in anything built since
around early 1990s.


Function    Wire color  DB9f Pin  Pport new/data  Pport old/status
()=Paddles  (Kempston)            (upto 4 Fire)   (no EPP needed)

Up          white          1      Data0  2        /Error   15
Down        blue           2      Data1  3        Select   13
Left        green          3      Data2  4        Paperend 12
Right       brown          4      Data3  5        /Ack     10
(AnalogY)   -              5      -      -        -        -
Fire/Btn    orange         6      Data4  6        Busy     11
(+5V)       -              7      -      -        -        -
Ground      black          8      Gnd    18       Gnd      18
(AnalogX)   -              9      -      -        -        -
- Fire2     -              -      Data5  7        -        -
- Fire3     -              -      Data6  8        -        -
- Fire4     -              -      Data7  9        -        -