TITLE 'iolib '
PAGE 55
; io lib .8
iolib segment byte public 'code'
; LIBRARY OF ASSEMBLER ROUTINES TO PERFORM LOW LEVEL IO
jmp iolibtest

; name VIDEOID
; Detects various video subsystems and monitors
; Caller Turboc
; void VIDEOID(VIDstruct)
;struct{ char Videosubsystem,display;} *VIDstruct[2];
;
;	subsystem id values
;
;	0 = none
;	1 = mda
;	2 = cga
;   3 = ega
;   4 = mcga
;   5 = vga
;   80H = hgc

;   display type
;	0 none
;	1 mda
;	2 cga
;	3 ega
;   4 ps2 mono
;   5 ps2 colour

;  values in VIDstruct[0] indicate the default system

ARGpVID EQU word ptr [bp+4]
VIDstruct STRUC
Video0Type db ?
Display0Type db ?
Video1Type db ?
Display1Type DB ?
VIDstruct ENDS
Device0 EQU word ptr Video0Type [di]
Device1 equ word ptr Video1Type [di]
mda equ 1
cga equ 2
ega equ 3
mcga equ 4
vga equ 5
hgc equ 80h
mdadisplay equ 1
cgadisplay equ 2




 public _MOUSEPRES,_MOUSESHOW,_MOUSEHIDE,_MOUSEX,_MOUSEY,_MOUSEBUT
_MOUSEBUT PROC far
	mov ax,3
	int 33h
	mov ax,bx
	ret
_MOUSEBUT ENDP


_MOUSEPRES PROC far
	mov ax,0
	int 33h
	ret
_MOUSEPRES ENDP


_MOUSESHOW PROC far
	mov ax,1
	int 33h
	ret
_MOUSESHOW ENDP


_MOUSEHIDE PROC far
	mov ax,2
	int 33h
	ret
_MOUSEHIDE ENDP

_MOUSEX PROC far
	mov ax,3
	int 33h
	mov ax,cx
	ret
_MOUSEX ENDP


_MOUSEY PROC far
	mov ax,3
	int 33h
	mov ax,dx
	ret
_MOUSEY ENDP
public _VGETCH
_VGETCH PROC far
    ; return character under cursor
    mov ah,8
	mov bh,0
	int 10h
	ret
_VGETCH ENDP

_ASMWRITE PROC  far
    public _ASMWRITE
    push bx
	push cx
	push dx
	push ds
    mov bx,[bp+4]
    mov cx,[bp+10]
    mov ah,40h

	lds dx,[bp+6]
    int 21h
    jnc endwrite
    neg ax
endwrite:
    pop ds
	pop dx
	pop cx
	pop bx
    ret
_ASMWRITE endp

_ASMREAD PROC   far
    public _ASMREAD
    push bx
	push cx
	push dx
	push ds
    mov bx,[bp+4]
    mov cx,[bp+10]
    mov ah,3fh

	lds dx,[bp+6]
    int 21h
    jnc endread
    neg ax
endread:
    pop ds
	pop dx
	pop cx
	pop bx
    ret
_ASMREAD endp


_ASMCREATE PROC  far
    public _ASMCREATE
    push bx
	push cx
	push dx
	push ds
    mov cx,[bp+8]
    mov ah,3ch

	lds dx,[bp+4]
    int 21h
    jnc endcr
    neg ax
endcr:
    pop ds
	pop dx
	pop cx
	pop bx
    ret
_ASMCREATE endp

iolib ends




;port addresses
index equ 3b4h
cntrl equ 3b8h
config equ 3bfh
; control codes
scrn_on equ 8
grph equ 2
textmode equ 20h
xcode segment public 'code'
	assume cs,ds:xcode

iolibtest :
    call _TMODE
	int 20h
gtable db 35h,2dh,2eh,7,5bh,2,57h,57h,2,3,0,0
ttable db 61h,50h,52h,0fh,19h,6,19h,19h,2,0dh,0bh,0ch
public _GMODE
;	GMODE puts 6845 into graphics mode
_GMODE proc far
	push es
	push ds
	mov ax,cs
	mov ds,ax
	mov al ,grph
	mov si, offset gtable
	mov bx,0
	mov cx,4000h
	call setmd
	pop ds
	pop es
	ret
_GMODE endp

public _TMODE
;	TMODE puts 6845 into text mode
_TMODE proc far
	push es
	push ds
	mov ax,cs
	mov ds,ax
	mov al ,textmode
	mov si,offset ttable
	mov bx,720h
	mov cx,2000
	call setmd
	pop ds
	pop es
	ret
_TMODE endp
setmd proc near
; si = parameter table
; cx number of words cleared
; bx = blank value
   push ds
   push es
   push ax
   push bx
   push cx
   push ax
   ; set config bit
   mov dx,config
   mov al,1
   out dx,al
   pop ax

   ; change mode with screen off
   mov dx,cntrl
   out dx,al
   ; init 6845
   mov ax,ds
   mov es,ax
   mov dx,index
   mov cx,12   ; 12 params
   xor ah,ah   ; start at reg 0
parms:
   mov al,ah
   out dx,al  ; out register num
   inc dx
   lodsb
   out dx,al
   inc ah    ; next reg
   dec dx
   loop parms
   pop cx    ; clear buffer
   mov ax,0b00h
   cld
   mov es,ax
   xor di,di
   pop ax
   jmp switchon
   rep stosw
   ; scrn on
   switchon:
   mov dx,cntrl
   pop ax
   add al,scrn_on
   out dx,al
   pop es
   pop ds
   ret
setmd endp


Bytesperline equ 90
OriginOffset equ 0
VideoBufferSeg EQU 0b000h


pixeladdrhgc proc near   ; see page 95 of Video Systems
    mov cl,bl
	shr ax,1
	rcr bx,1
	shr ax,1
	rcr bx,1
	shr bx,1
	mov ah, Bytesperline
	mul ah
	add bx,ax
	add bx,OriginOffset
	mov ax,VideoBufferSeg
	mov es,ax
	and cl,7
	xor cl,7
	mov ah, 1
	ret
pixeladdrhgc endp

;  SETPIXELHGC(x,y,n) int x,y;
;					  int n ; /* colour */
argx equ word ptr [bp+6]
argy equ word ptr [bp+8]
argn equ byte ptr [bp+10]
public _SETPIXELHGC
    db 'setpixelhgc'
_SETPIXELHGC proc far
    push bp
	mov bp,sp
	mov ax,argy
	mov bx,argx
	call pixeladdrhgc
	mov al ,argn
	shl ax,cl
	jmp word ptr cs: setpixelop04
setpixelop04 dw replacepixelop04
replacepixelop04: not ah
	and es:[bx],ah
	or es:[bx],al
	jmp short l02

andpixelop04: not ah
	or al,ah
	and es:[bx],al
	jmp short l02

orpixelop04: or es:[bx],al
	jmp short l02

xorpixelop04: xor es:[bx],al
l02: mov sp,bp
	pop bp
	ret

_SETPIXELHGC endp
 public _BIOSTEXTMODE
_BIOSTEXTMODE proc far
	push bp
	mov bp,sp
	push si
	push di
    mov ax,7
	int 10h

	pop di
	pop si
	mov sp,bp
	ret
     endp

xcode ENDS


 end