INT 15,84 - Joy-Stick Support

AH = 84h

DX = 0 to read the current switch settings

= 1 to read the ~joystick~ position (resistive inputs)

on return (DX=0, read switch setting):

CF = 0 if successful

= 1 if error

AH = 80h error code if CF set on PC

= 86h error code if CF set on XT before 11/8/82

AL = switch settings in bits 7-4 (if read switch function)

on return (DX=1, read joystick position):

AX = A(X)

BX = A(Y)

CX = B(X)

DX = B(Y)