83:ROMCalls:4010

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Synopsis

Official Name: KbdScan

Call Address: 4010

This routine scans the keyboard for any key presses and updates the memory location kbdScanCode.

Inputs

  • none

Outputs

Registers Destroyed

  •  ??

Comments

Normally this routine is called by the interrupt handler. If interrupts are not enabled, this can be used prior to the Getcsc romcall to achieve the same results.

Key repeat is handled here, when scanning the keyboard. If any of the arrow keys or DEL is held, they will first be repeated after about 48 calls and every 10 after the first. Holding other keys will not update kbdScanCode until the key is released.