IF2 Joystick programming

The two joysticks appear to be the same as the top row on the keyboard, and are connected thus:

Key	Joystick 2  		Key	Joystick 1
 1	Left			 6	Left
 2	Right			 7	Right
 3	Down			 8	Down
 4	Up			 9	Up
 5	Fire			10	Fire

They can be read from BASIC using INKEY$, but this function will read only one key; it would not recognise Left and Fire together, for example.

The alternative - and more sensible - way of reading the joysticks is to use the IN function.

IN 61438 reads joystick 1   IN 63486 reads joystick 2

bit 0 'fire'                bit 4 'fire'
bit 1 'up'                  bit 3 'up'
bit 2 'down'                bit 2 'down'
bit 3 'right'               bit 1 'right'
bit 4 'left'                bit 0 'left'