DP Tool Club 15/CD_ASCQ_15_070894.iso/news/sorcpak/fpoly256/gxsppt.asm

Assembly Source File | 1991-12-17 | 5KB | 333 lines

    TITLE    GSPPT - 320x200x16 mode support
    NAME    GSPPT


    COMMENT    $

    Name:        GXSPPT

        Written and (c) by Dave Stampe 9/11/91
        Not for commercial use, so get permission
        before marketing code using this stuff!
        For private PD use only.

        $

        .MODEL large
        .CODE

 ;
 ; void vsync();        /* waits for vert. sync pulse */
 ;
        PUBLIC    _vsync

_vsync    proc    far

    push    bp
    mov    bp,sp
    mov        dx,03DAh
    in        al,dx        ; test if 0
    test        al,8
    je    short @11@218
@11@122:
    in        al,dx
    nop
    test        al,8            ; wait for 0
    jne    short @11@122
@11@218:
    in        al,dx
    nop
    test        al,8            ; wait for 1
    je    short @11@218
    pop    bp
    ret

_vsync    endp

 ;
 ; void setup_hdwe(int mode);    /* sets up VGA for line, poly draw */
 ;                              /* modes are: 0=PUT, 1=OR,         */
 ;                /*          2=AND, 3=XOR         */
 ;                /* only PUT for X-mode             */

        PUBLIC    _setup_hdwe

_setup_hdwe    proc    far

    push    bp
    mov    bp,sp
    mov    dx,03CEH
    mov    ax,00008h               ; all display copy bits
    out    dx,ax

    mov    dx,03c4h        ; prepare plane mask reg. for access
    mov    ax,0f02h
    out    dx,ax
    pop    bp
    ret

_setup_hdwe    endp

 ;
 ; void reset_hdwe()
 ;

        PUBLIC    _reset_hdwe

_reset_hdwe    proc    far

    push    bp
    mov    bp,sp
    mov    dx,03CEH
    mov    ax,0FF08h               ; all CPU data bits
    out    dx,ax

    mov    dx,03c4h        ; prepare plane mask reg. for access
    mov    ax,0f02h
    out    dx,al
    pop    bp
    ret

_reset_hdwe    endp

 ;
 ; int clr_page(int page, int color);    /* clear page to color */
 ;
 ;  /* returns 0 if OK, 1 if bad page */

        PUBLIC    _clr_page

_clr_page    proc    far

    push    bp
    mov    bp,sp
    dec    sp
    dec    sp
    push    di
    cld
    mov     cx,word ptr [bp+6]
    cmp    cx,3               ; check for valid page
    jle    short @14@74
    mov    ax,65535
    jmp    short @14@482
@14@74:
    call    far ptr _setup_hdwe     ; reset to default VGA mode
    cld
    mov    ax,0A000h
    mov    es,ax
    mov    bl,BYTE PTR [bp+8]
    mov    bh,0ffh            ; figure what entry to read
    mov    al,es:[bx]          ; read entry into latches

    mov     ax,word ptr [bp+6]
    mov    cx,16000
    mul    cx
    mov    di,ax

    rep    stosb
    call    far ptr _reset_hdwe
    xor    ax,ax
@14@482:
    pop    di
    mov    sp,bp
    pop    bp
    ret

_clr_page    endp

   ;
   ;    int copy_page(int source, int dest)
   ;
   ;    /* returns 0 if OK, 1 if bad page */

        PUBLIC    _copy_page

_copy_page    proc    far

    push    bp
    mov    bp,sp
    sub    sp,4
    push    si
    push    di
    cmp    word ptr [bp+6],3
    jg    short @15@74            ; check for valid page #'s
    cmp    word ptr [bp+8],3
    jle    short @15@98
@15@74:
    mov    ax,65535
    jmp    short @15@506
@15@98:
    call    far ptr _setup_hdwe       ; write VGA state
    push    ds
    cld
    mov    ax,0A000h
    mov    es,ax
    mov    ds,ax
    mov    cx,16000
    mov    ax,word ptr [bp+6]        ; compute source address
    mul    cx
    mov    si,ax
    mov    ax,word ptr [bp+8]    ; compute dest. address
    mul    cx
    mov    di,ax

    rep    movsb

    call    far ptr _reset_hdwe
    pop    ds
    xor    ax,ax
@15@506:
    pop    di
    pop    si
    mov    sp,bp
    pop    bp
    ret

_copy_page    endp


 ;
 ; void vga_reg(int reg)     /* integer: lsby=reg(0=color), msby=value */
 ;

        PUBLIC    _vga_reg

_vga_reg    proc    far

    push    bp
    mov    bp,sp
    mov    dx,03CEH
    mov    ax,WORD PTR [bp+6]
    out    dx,ax
    pop    bp
    ret

_vga_reg    endp



 ;
 ; void load_color(int color)    /* integer: loads latches with color */
 ;

        PUBLIC    _load_color

_load_color    proc    far

    push    bp
    mov    bp,sp
    mov    ax,0a000h
    mov    es,ax
    mov    bl,BYTE PTR [bp+6]
    mov    bh,0ffh        ; figure what entry to read
    mov    al,es:[bx]      ; read entry into latches
    pop    bp
    ret

_load_color    endp


 ;
 ; void _set_vmode(int mode)    /* enters video mode thru BIOS */
 ;                              /* mode: clear if MSB not 0    */
 ;                /* mode 14h = X-mode           */

        PUBLIC    _set_vmode

_set_vmode    proc    far

    push    bp
    mov    bp,sp

    mov    ah,0
    mov    al,BYTE PTR [bp+6]
    mov    bl,al
    and    bl,07fh
    cmp    bl,14h
    jz    setxmode
    int    10h
    pop    bp
    ret

setxmode:
    mov    ah,0        ; set 256-color mode
    mov    al,13h
    int    10h

    mov    dx,03c4h    ; convert to X-mode addressing
    mov    ax,0604h        ; chain mode off
    out     dx,ax

    mov    dx,03d4h
    mov    ax,0014h        ; doubleword off
    out    dx,ax
    mov    ax,0E317h       ; byte mode on
    out    dx,ax

    call     far ptr _reset_hdwe

    mov    ax,WORD PTR[bp+6]
    test    al,080h
    jnz    dontclear

    mov    ax,0f02h
    out    dx,ax        ; clear all planes at once
    mov    ax,0a000h
    mov    es,ax
    xor    di,di
    mov    cx,0ffffh
    xor    ax,ax
    rep    stosb

    mov    di,0ff00h    ; setup latch color table
    mov    cx,100h
    xor    al,al
ctloop:    stosb
    inc    al
    loop    ctloop

dontclear:
    pop    bp
    ret

_set_vmode    endp


 ;
 ; void _set_vpage(int page)    /* sets video page */
 ;

        PUBLIC    _set_vpage

_set_vpage    proc    far

    push    bp
    mov    bp,sp
    mov    ah,5
    mov    al,BYTE PTR [bp+6]
    xor    ah,ah
    cmp    al,4        ; check page #
    jae    badpage

    mov    bx,16000
    mul    bx

    mov    bh,ah
    mov    ah,al           ; page # -> address
    mov    al,0dh
    mov    bl,0ch

    mov    dx,03d4h        ; set CRTC address
    out    dx,ax
    mov    ax,bx
    out    dx,ax
badpage:
    pop    bp
    ret

_set_vpage    endp


        end