DOSGame/trunk/BIOSFUNC.ASM

; AL = Character
BIOS_WriteTTYChar:
    ;MOV AL, [0]
    MOV AH, 0Eh
    INT 10h
    RET

BIOS_SetVideoMode13H:
    CMP BYTE [CurrentVideoMode], 0x13 ; Prevent a switch if we're already mode 13.
    ; This prevents clearing the framebuffer if clearing wasn't intended
    JE .already
    MOV AX, 0x0013
    INT 10h
    MOV BYTE [CurrentVideoMode], 0x13
    .already:
    RET

BIOS_SetVideoMode03H:
    CMP BYTE [CurrentVideoMode], 0x03 ; Prevent a switch if we're already mode 03.
    ; This prevents clearing the framebuffer if clearing wasn't intended, and also whenever
    ; we show an error in fallback mode, and then call an error handler, the latter will not
    ; clear the screen by switching from 03 to 03.
    JE .already
    MOV AX, 0x0003
    INT 10h
    MOV BYTE [CurrentVideoMode], 0x03
    .already:
    RET
Revision:	4
Committed:	Wed Feb 11 15:26:06 2026 UTC (8 weeks, 3 days ago) by figdor32
File size:	852 byte(s)
Log Message:	Initial check-in
#	User	Rev	Content
1	figdor32	4	; AL = Character
2			BIOS_WriteTTYChar:
3			;MOV AL, [0]
4			MOV AH, 0Eh
5			INT 10h
6			RET
7
8			BIOS_SetVideoMode13H:
9			CMP BYTE [CurrentVideoMode], 0x13 ; Prevent a switch if we're already mode 13.
10			; This prevents clearing the framebuffer if clearing wasn't intended
11			JE .already
12			MOV AX, 0x0013
13			INT 10h
14			MOV BYTE [CurrentVideoMode], 0x13
15			.already:
16			RET
17
18			BIOS_SetVideoMode03H:
19			CMP BYTE [CurrentVideoMode], 0x03 ; Prevent a switch if we're already mode 03.
20			; This prevents clearing the framebuffer if clearing wasn't intended, and also whenever
21			; we show an error in fallback mode, and then call an error handler, the latter will not
22			; clear the screen by switching from 03 to 03.
23			JE .already
24			MOV AX, 0x0003
25			INT 10h
26			MOV BYTE [CurrentVideoMode], 0x03
27			.already:
28			RET