83Plus:BCALLs:4018
Synopsis
Official Name: GetCSC
BCALL Address: 4018
This routine loads the most recent scan code into register A.
Inputs
- Set appWantDiagonalKeys, (iy + mouseFlag1) to receive diagonal arrow key presses (but see comments)
Outputs
- A=(kbdScanCode)
- May contain diagonal arrow key presses. Add these equates to your ti83plus.inc:
skDownLeft EQU 252 skDownRight EQU 250 skUpLeft EQU 245 skUpRight EQU 243
- (kbdScanCode)=0
- kbdSCR,(iy+kbdFlags) reset
Registers Destroyed
- HL=kbdScanCode
Comments
This routine expects that either interrupts are enabled or KbdScan was called manually. Either of these routines will check the keyboard and load the appropriate scan code into the memory location kbdScanCode and set the flag kbdSCR,(iy+kbdFlags).
When polled by the OS interrupt with KbdScan, only the arrow keys and DEL will repeat if held. All other keys will be returned only once until released and pressed again.
If you set appWantDiagonalKeys, (iy + mouseFlag1) GetKey will return garbage values for diagonal arrow key presses. In particular, two of the combinations share the same value. So that flag obviously isn't meant for use with GetKey. You should not return to the OS with it set for that reason.
