Spellbound (48k): Routine at 37959

37959: Capture Fuller joystick input

Used by the routine at 37876.

Input
HL	23485 (store for currently active keyboard press / joystick action)

Output
A	Stored key-press (bits: 0=LEFT, 1=RIGHT, 2=UP, 3=DOWN, 4=FIRE)

37959

LD C,127

Load 127 (Fuller port number) into C

37961

IN A,(C)

Read byte from port 127 (i.e. read state of joystick)

37963

BIT 2,A

If joystick moved left...

37965

CALL Z,38060

...store a LEFT input from control device

37968

BIT 3,A

If joystick moved right...

37970

CALL Z,38063

...store a RIGHT input from control device

37973

BIT 1,A

If joystick moved down...

37975

CALL Z,38069

...store a DOWN input from control device

37978

BIT 0,A

If joystick moved up...

37980

CALL Z,38066

...store an UP input from control device

37983

BIT 7,A

If fire button pressed...

37985

CALL Z,38072

...store a FIRE input from control device

37988

LD A,(HL)

Return stored joystick movement in A

37989

RET

Return