;
; Video support routines
;****************************************************************************
;* *
;* *
;* part of NCSA Telnet *
;* by Tim Krauskopf, VT100 by Gaige Paulsen, Tek by Aaron Contorer *
;* *
;* National Center for Supercomputing Applications *
;* 152 Computing Applications Building *
;* 605 E. Springfield Ave. *
;* Champaign, IL 61820 *
;* *
;****************************************************************************
;
NAME INITVID
;Microsoft EQU 1
;Lattice EQU 1
ifndef Microsoft
ifndef Lattice
if2
%out
%out ERROR: You have to specify "/DMicrosoft" or "/DLattice" on the
%out MASM command line to determine the type of assembly.
%out
endif
end
endif
endif
X EQU 6
MONO_SEG EQU 0b000h ; Standard display segments
COLOR_SEG EQU 0b800h
ifdef Microsoft
;DGROUP group _DATA
;_DATA segment public 'DATA'
; assume DS:DGROUP
.MODEL LARGE
.DATA
else
INCLUDE DOS.MAC
SETX
DSEG
endif
video_segment DW COLOR_SEG ; Display memory segment address
video_type DB 0ffh ; Display combination code
video_iscolor DB 01h ; 1=color, 0=monochrome
video_mode DB 03h ; Video display mode
video_page DB 00h ; Video Display Page
video_rows DB 25 ; Number of Text rows
video_cols DB 80 ; Number of Text columns
ifdef Microsoft
;_DATA ends
;
;_TEXT segment public 'CODE'
; assume CS:_TEXT
.CODE
PUBLIC _INITVIDEO,_GETVCONFIG
else
ENDDS
PSEG
PUBLIC INITVIDEO,GETVCONFIG
endif
;
; Routines for general use
;
;
;************************************************************************
; initvideo
;
; Determines the active display adapter and various display parameters
;
ifdef Microsoft
_initvideo proc far
else
initvideo proc far
endif
PUSH BP
MOV BP, SP
PUSH DS
PUSH ES
PUSH SI
PUSH DI
MOV AH,0FH ; Read Video information
INT 10H
MOV video_mode,AL ; Video Display Mode
MOV video_page,BH ; Video Display Page
MOV video_cols,AH ; Number of Text Columns
MOV video_segment,MONO_SEG ; Assume monochrome for now
MOV video_iscolor,0 ;
INT 11H ; Read Equipment list
AND AL,00110000b ; Isolate Video bits
CMP AL,00110000b ; Was it mono?
JE find_adapter ; Yes
MOV video_segment,COLOR_SEG ; Else, set color display
MOV video_iscolor,1 ;
find_adapter:
CALL ps2_state ; Read PS/2 video state
JNZ adapter_set ; Done, if supported
CALL ega_state ; Read EGA video state
JNZ adapter_set ; Done, is supported
CALL cga_state ; Determine CGA or mono
adapter_set:
SUB AX,AX ; Adjust dsplay segment for current vide page
MOV ES,AX ;
MOV AX,ES:[044EH] ;
MOV CL,4
SHR AX,CL
ADD video_segment,AX
POP DI
POP SI
POP ES
POP DS
POP BP
ret
ifdef Microsoft
_initvideo endp
else
initvideo endp
endif
;************************************************************************
; ps2_state
;
; This procedure attempts to access ps/2 compatible ROM BIOS video
; services. The zero flag is set if they aren't supported
;
ps2_state proc near
MOV AX,1A00H ; Read PS/2 video state
INT 10H
CMP AL,1AH ; Was function supported?
LAHF ; Toggle zero flag (zf=1 if al is not equal to 1ah)
XOR AH,01000000b ;
SAHF
JZ no_ps2 ; PS/2 BIOS not present
MOV video_type,BL ; Save active display code
MOV AX,1130h ; Read Font Code
SUB BH,BH ; Font Code (not used)
INT 10h ;
INC DL ; Adjust row count (clear zf)
MOV video_rows,DL ; and save
no_ps2:
RET
ps2_state endp
;************************************************************************
; ega_state
;
; If PS/2 compatible ROM BIOS is not present, this procedure attempts
; to access the EGA ROM BIOS video services
;
ega_state proc near
MOV AH,12H ; Read EGA video state
MOV BL,10H
INT 10H
CMP BL,10H ; Was Function supported?
JE no_ega ; No, EGA BIOS not present
CMP video_iscolor,BH ; Is EGA the active display?
JE no_ega ; No, find active display
ADD BH,4 ; Else, calculate display code
MOV video_type,BH ; and save
MOV AX,1130H ; Read Font code
SUB BH,BH ; Font Code (not used)
INT 10H
INC DL ; Adjust row count (clear zf)
MOV video_rows,DL ; and save
no_ega:
RET
ega_state endp
;************************************************************************
; cga_state
;
; If neither PS/2 compatible ROM BIOS nor EGA ROM BIOS is present,
; this procedure is called. It simply assumes 25 text rows and sets
; video_type to MDA or CGA depending on the value of video_iscolor
;
cga_state proc near
MOV video_rows,25 ; If we get here, must be 25 rows
MOV video_type,01H ; Assume MDA adapter for now
CMP video_iscolor,0 ; Is it mono?
JE no_cga ; Yes
MOV video_type,02H ; Else set CGA display adapter
no_cga:
RET
cga_state endp
;************************************************************************
; getvconfig
;
; This routine fills a buffer with the current videio paremeter values.
; Note: initvideo() must be called first in order for this procedure
; to return meaningful values.
;
; Usage: void getvconfig(struct vidinfo *)
;
; Where: struct vidinfo {
; int segment;
; int type;
; int iscolor;
; int mode;
; int page;
; int rows;
; int columns;
; };
;
ifdef Microsoft
_getvconfig proc far
else
getvconfig proc far
endif
PUSH BP
MOV BP,SP
PUSH ES
PUSH DI
PUSH SI
CLD ; All moves forward
IF @DataSize
LES DI,[BP+X] ; Get the Pointer to the buffer
ELSE
MOV DI,[BP+X] ; Get the Pointer to the buffer
PUSH DS
POP ES
ENDIF
MOV SI,OFFSET video_segment ; Get the offset of the start of the videio information
MOVSW ; Copy the video segment
MOV CX,6 ; Copy six more byte values
XOR AH,AH ; Clear the top part of the transfer register
Copy_Loop:
LODSB ; Move each byte from the video parameters
STOSW ; Into a word in the structure
LOOP Copy_Loop
POP DI
POP SI
POP ES
POP BP
RET
ifdef Microsoft
_getvconfig endp
else
getvconfig endp
endif
ifdef Microsoft
;_TEXT ends
else
ENDPS
endif
END
