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|
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
.ALPHA ;AN000;
.XLIST ;AN000;
INCLUDE STRUC.INC ;AN000;
.LIST ;AN000;
;
PUBLIC MONO, CGA, EGA, LCD ;AN000;
PUBLIC ACTIVE, ALTERNATE ;AN000;
;
EXTRN IN_CURNOR:WORD ;AN000;JW
;
DATA SEGMENT BYTE PUBLIC 'DATA' ;AN000;
MONO EQU 1 ;AN000;
CGA EQU 2 ;AN000;
EGA EQU 3 ;AN000;
LCD EQU 4 ;AN000;
;
READ_DISPLAY EQU 1AH ;AN000;
ALT_SELECT EQU 12H ;AN000;
EGA_INFO EQU 10H ;AN000;
MONOCHROME EQU 1 ;AN000;
BASE_COLOR EQU 0B800H ;AN000;
BASE_MONO EQU 0B000H ;AN000;
GET_SYS_ID EQU 0C0H ;AN000;
LCD_MODEL EQU 0F9H ;AN000;
GET_STATUS EQU 43H ;AN000;
ON EQU 1 ;AN000;
;
SYSTEM_ID STRUC ;AN000;
DW ? ;AN000;
MODEL_BYTE DB ? ;AN000;
SYSTEM_ID ENDS ;AN000;
;
ACTIVE DB 0 ;AN000;
ALTERNATE DB 0 ;AN000;
;
DATA ENDS ;AN000;DATA
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
;
;
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
SERVICE SEGMENT PARA PUBLIC 'SERVICE' ;AN000;segment for far routine
ASSUME CS:SERVICE,DS:DATA ;AN000;
;
PUBLIC VIDEO_CHECK ;AN000;
VIDEO_CHECK PROC FAR ;AN000;
PUSH AX ;AN000;
PUSH BX ;AN000; save all registers
PUSH CX ;AN000;
PUSH DX ;AN000;
PUSH SI ;AN000;
PUSH DI ;AN000;
PUSH ES ;AN000;
XOR AL,AL ;AN000;
MOV AH,READ_DISPLAY ;AN000; check for VGA first.
INT 10H ;AN000;
.IF <AL EQ READ_DISPLAY> ;AN000; VGA present?
.SELECT ;AN000; yes....BL contains active..
.WHEN <BL EQ MONO> ;AN000; display code.
MOV ACTIVE,MONO ;AN000;
.WHEN <BL EQ CGA> ;AN000;
MOV ACTIVE,CGA ;AN000;
.WHEN <BL A CGA> ;AN000;
MOV ACTIVE,EGA ;AN000;
.ENDSELECT ;AN000;
.SELECT ;AN000; ...and BH contains alternate..
.WHEN <BH EQ MONO> ;AN000; display code.
MOV ALTERNATE,MONO ;AN000;
.WHEN <BH EQ CGA> ;AN000;
MOV ALTERNATE,CGA ;AN000;
.WHEN <BH A CGA> ;AN000;
MOV ALTERNATE,EGA ;AN000;
.ENDSELECT ;AN000;
.ELSE ;AN000; VGA not there..check for EGA.
MOV AH,ALT_SELECT ;AN000;
MOV BL,EGA_INFO ;AN000;
INT 10H ;AN000;
.IF <BL NE EGA_INFO> ;AN000; EGA present?
MOV ACTIVE,EGA ;AN000; yes....set as active.
.IF <BH EQ MONOCHROME> ;AN000; if monochrome attached to EGA then..
MOV AX,BASE_COLOR ;AN000; check if CGA is an alternate.
CALL CHECK_BUFF ;AN000;
.IF <AH EQ AL> ;AN000; CGA there?
MOV ALTERNATE,CGA ;AN000; yes....alternate display.
.ENDIF ;AN000;
.ELSE ;AN000; if color attached to EGA then...
MOV AX,BASE_MONO ;AN000; check if monochrome is an alternate.
CALL CHECK_BUFF ;AN000;
.IF <AH EQ AL> ;AN000; MONO there?
MOV ALTERNATE,MONO ;AN000; yes....alternate display.
.ENDIF ;AN000;
.ENDIF ;AN000;
.ELSE ;AN000; EGA not present so...
MOV AH,GET_SYS_ID ;AN000; check for LCD.
INT 15H ;AN000;
.IF <ES:[BX].MODEL_BYTE EQ LCD_MODEL> AND ;AN000; if model byte says convertible..
MOV AH,GET_STATUS ;AN000; and..
INT 15H ;AN000;
.IF <BIT AL NAND ON> ;AN000; if LCD screen attached..then
MOV ACTIVE,LCD ;AN000; set LCD as active display.
.ELSE ;AN000;
MOV AX,BASE_MONO ;AN000; not LCD...check for..
CALL CHECK_BUFF ;AN000; MONO....
.IF <AH EQ AL> ;AN000;
MOV ACTIVE,MONO ;AN000; MONO found...set as active.
MOV IN_CURNOR,0B0CH ;AN000;JW set mono cursor size
.ENDIF ;AN000;
MOV AX,BASE_COLOR ;AN000; ..and check for color.
CALL CHECK_BUFF ;AN000;
.IF <AH EQ AL> ;AN000;
MOV ALTERNATE,CGA ;AN000; color found...set CGA as alternate.
.ENDIF ;AN000;
.ENDIF ;AN000;
.ENDIF ;AN000;
.ENDIF ;AN000;
POP ES ;AN000;
POP DI ;AN000; restore registers.
POP SI ;AN000;
POP DX ;AN000;
POP CX ;AN000;
POP BX ;AN000;
POP AX ;AN000;
RET ;AN000;
VIDEO_CHECK ENDP ;AN000;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;
;
;
;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
CHECK_BUFF PROC NEAR ;AN000; write to video buffer to see if it is present
PUSH DS ;AN000;
MOV DS,AX ;AN000; load DS with address of buffer
MOV CH,DS:0 ;AN000; save buffer information (if present)
MOV AL,55H ;AN000; prepare to write sample data
MOV DS:0,AL ;AN000; write to buffer
PUSH BX ;AN000; terminate the bus so that lines..
POP BX ;AN000; are reset
MOV AH,DS:0 ;AN000; bring sample data back...
MOV DS:0,CH ;AN000; repair damage to buffer
POP DS ;AN000;
RET ;AN000;
CHECK_BUFF ENDP ;AN000;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
SERVICE ENDS ;AN000;
END ;AN000;
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