change virtkbd char from null to htab

This commit is contained in:
Tibo Ulens 2021-11-08 23:47:02 +01:00
parent 5d6a0e231c
commit 312332cdda

View file

@ -8,6 +8,8 @@ VIDEO_MODE equ 0x3 ; 80x25 screen, text mode
PIT_MODECOMMAND_PORT equ 0x43 ; programmable interval timer mode/command port (used for speaker)
PIT_CH2_DATA_PORT equ 0x42 ; PIT channel 2 data port
VIRTUAL_KBD_CHAR equ 0x09 ; character to detect if a command is comming from the virtual keyboard (htab)
;; see http://www.ctyme.com/intr/int-10.htm for interrupts
start:
@ -66,9 +68,9 @@ int 0x10
mov ah, 0x00 ; Read character
int 0x16
;; a null character will be sent before every command from the virtual keyboard
;; so if a null is detected go to the virtual_kbd_loop instead
cmp al, 0x00 ; null
;; a special character will be sent before every command from the virtual keyboard
;; so if that character is detected go to the virtual_kbd_loop instead
cmp al, VIRTUAL_KBD_CHAR
je .virtual_kbd_loop_init
cmp al, 0x08 ; backspace