home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Cream of the Crop 1
/
Cream of the Crop 1.iso
/
PROGRAM
/
DJSRC106.ARJ
/
TRIDNT89.ASM
< prev
next >
Wrap
Assembly Source File
|
1992-04-08
|
4KB
|
229 lines
; This is file TRIDNT89.ASM
;
; Copyright (C) 1991 DJ Delorie, 24 Kirsten Ave, Rochester NH 03867-2954
;
; This file is distributed under the terms listed in the document
; "copying.dj", available from DJ Delorie at the address above.
; A copy of "copying.dj" should accompany this file; if not, a copy
; should be available from where this file was obtained. This file
; may not be distributed without a verbatim copy of "copying.dj".
;
; This file is distributed WITHOUT ANY WARRANTY; without even the implied
; warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
;
cseg segment byte public 'code'
assume cs:cseg, ds:cseg, es:cseg, ss:nothing
dw offset init_routine
dw offset paging_routine
dw 0 ; set to 1 if separate read & write windows or
; only 64K of video RAM (ie: no paging)
def_tw dw 80 ; filled in by go32 if GO32 env. var. is set
def_th dw 25
def_gw dw 640
def_gh dw 480
;--------------------------------------------------------------------------
; Entry: AX=mode selection
; 0=80x25 text
; 1=default text
; 2=text CX cols by DX rows
; 3=biggest text
; 4=320x200 graphics
; 5=default graphics
; 6=graphics CX width by DX height
; 7=biggest non-interlaced graphics
; 8=biggest graphics
;
; NOTE: This runs in real mode, but don't mess with the segment registers.
;
; Exit: CX=width (in pixels or characters)
; DX=height
init_table label word
dw offset init_0
dw offset init_1
dw offset init_2
dw offset init_3
dw offset init_4
dw offset init_5
dw offset init_6
dw offset init_7
dw offset init_8
init_routine proc far
cmp ax,8
jbe valid_req
ret
valid_req:
shl ax,1
mov bx,ax
jmp init_table[bx]
init_0: ; 80x25 text
mov ax,3
int 10h
mov cx,80
mov dx,25
ret
init_1: ; default text
mov cx,def_tw
mov dx,def_th
jmp init_2
init_2_table label word
dw 01h, 40, 25
dw 03h, 80, 25
init_2_tend label word
init_2: ; CX*DX text
mov si,offset init_2_table
init_2a:
cmp [si+2],cx
jb init_2b
cmp [si+4],dx
jb init_2b
; got a big enough one!
jmp init_2c
init_2b:
cmp si,offset init_2_tend - 6
je init_2c
add si,6
jmp init_2a
init_2c:
mov ax,[si]
push si
int 10h
pop si
mov cx,[si+2]
mov dx,[si+4]
ret
init_3: ; biggest text
mov ax,[init_2_tend-6]
int 10h
mov cx,[init_2_tend-4]
mov dx,[init_2_tend-2]
ret
init_4: ; 320x200 graphics
mov ax,13h
int 10h
mov cx,320
mov dx,200
ret
init_5: ; default graphics - should be 640x480 if supported
mov cx,def_gw
mov dx,def_gh
jmp init_6
init_6_table label word
dw 13h, 320, 200
dw 5ch, 640, 400
dw 5dh, 640, 480
dw 5eh, 800, 600
dw 62h, 1024, 768
init_6_tend label word
init_6: ; CX*DX graphics
mov si,offset init_6_table
init_6a:
cmp [si+2],cx
jb init_6b
cmp [si+4],dx
jb init_6b
; got a big enough one!
jmp init_6c
init_6b:
cmp si,offset init_6_tend - 6
je init_6c
add si,6
jmp init_6a
init_6c:
mov ax,[si]
push si
int 10h
pop si
mov cx,[si+2]
mov dx,[si+4]
ret
init_7: ; biggest non-interlaced graphics
mov ax,5eh
int 10h
mov cx,800
mov dx,600
ret
init_8: ; biggest graphics
mov ax,62h
int 10h
mov cx,1024
mov dx,768
ret
init_routine endp
;--------------------------------------------------------------------------
; Entry: AH=read page
; AL=write page
;
; NOTE: This runs in protected mode! Don't mess with the segment registers!
; This code must be relocatable and may not reference any data!
;
; Exit: VGA configured.
; AX,BX,CX,DX,SI,DI may be trashed
;
; Code derived from VGAKIT version 3.4
; Copyright 1988,89,90 John Bridges
assume ds:nothing, es:nothing
paging_routine proc far
mov cx,ax
mov dx,3ceh ;set page size to 64k
mov al,6
out dx,al
inc dl
in al,dx
dec dl
or al,4
mov ah,al
mov al,6
out dx,al
inc dx
xchg ah,al
out dx,al
dec dx
mov dl,0c4h ;switch to BPS mode
mov ax,000bh
out dx,al
inc dx
xchg ah,al
out dx,al
dec dx
in al,dx
mov ah,cl
xor ah,2
mov dx,3c4h
mov al,0eh
out dx,al
inc dx
xchg ah,al
out dx,al
dec dx
ret
paging_routine endp
;--------------------------------------------------------------------------
cseg ends
end