Outils pour utilisateurs

Outils du site


Table des matières

INT 0x15 - 0x4f - Keyboard Intercept (BIOS date specific)


reg value descr
AH 0x4f
AL val scan code
CF 1 set to 1 (via STC instruction)


reg descr
AH 80h, CF Set (PC, PCjr)
86h, CF set (XT BIOS 11/08/82, AT BIOS 1/10/84)
AL CF set, new scan code
CF clear, original scan code

Notes & Comments

  • available with XT BIOS after 11/8/82, AT BIOS after 1/10/84
  • called by INT 9, makes allowance for keyboard translation
  • normally returns the scan code in AL, with CF set
  • if function returns with CF clear, INT 9 ignores keystroke
  • do not rely on this function being called for each INT 9 since any user INT 9 handler can exit prematurely and circumvent this function.


back2root/ibm-pc-ms-dos/interrupts/int_15/int_15_4f.txt · Dernière modification : 2024/04/08 08:23 de