HPAVC/HPAVC CD-ROM.iso/BIRTHSRC.ZIP/INTMISC.INC

Text File | 1993-11-23 | 7KB | 348 lines

;╔════════════════════════════════════════════════╗
;║  Name:Video_Sync_And_Keyboard_INT_Routines      ║
;║                                                ║
;║  Modified:23-Nov-93                   FB ║
;╚════════════════════════════════════════════════╝
;
;--------------------------------------------------------------
;
; SetINT8
;   -INT8handler
; RestoreINT8
;
; SetINT9
;   -INT9handler
; RestoreINT9
;
; DisableKbd
; EnableKbd
;
; WaitBorder
; GetRasterline
; WaitRasterline
;
;-----------------------------------------------------------------

frametime    dw ?
oldINT8     dd ?
oldINT9     dd ?

;-----------------------------------------------------------------
INT8handler PROC FAR

    ;timer interrupt
    push    ax
    push    dx

    mov    al,20h
    out    20h,al

    mov    dx,3dah
int8_1: in    al,dx
    test    al,8
    jz    int8_1       ; wait for VR
       ;call waitborder

    mov    al,34h       ; pulse
    out    43h,al
    mov    al,byte ptr cs:[frametime]
    out    40h,al
    mov    al,byte ptr cs:[frametime+1]
    out    40h,al

    ;NOTE: we are now in a VR!
    ;if housekeeper takes relative long you might want to
    ;move it to the beginning of the handler and adjust
    ;the interrupt timing s.t. the prog gets interrupted
    ;some additional scan lines before the VR.
    sti
    call    housekeeper
    cli

    pop    dx
    pop    ax
    iret
INT8handler ENDP

;-----------------------------------------------------------------
; SetINT8 - Sets Timer Interrupt (8) - timer synchronized with VR
;    IN     : -
;   OUT     : -
;  Modified : ax,dx
;  Vars Used: oldINT8,frametime


SetINT8 PROC NEAR
    cli
    ;set up timer int vector
    push    es
    xor    ax,ax
    mov    es,ax
    mov    ax,es:[8*4]
    mov    word ptr cs:oldINT8[0],ax
    mov    ax,es:[8*4+2]
    mov    word ptr cs:oldINT8[2],ax
    mov    ax,offset INT8handler
    mov    es:[8*4],ax
    mov    es:[8*4+2],cs
    pop    es
    sti

    ;find time it takes from VR to next VR
    call    waitborder
    ;set timer to max period 65536
    mov    al,34h        ;pulse
    out    43h,al
    mov    al,0
    out    40h,al
    mov    al,0
    out    40h,al

    call    waitborder
    xor    al,al        ;latch present counter value
    out    43h,al
    in    al,40h        ;read LO
    mov    ah,al
    in    al,40h        ;read HI
    xchg    al,ah

    ;counter counts down from 65536
    ;to find time: (65536-HILO)=-HILO
    neg    ax

    ;frametime = frametime-(frametime/128)
    ;make sure we never miss the beginning of a VR
    mov    dx,ax
    shr    ax,7        ;7 works fine with short housekeeper
    sub    dx,ax
    mov    cs:frametime,dx     ;length of one frame

    ;set timer
    call    waitborder
    mov    al,34h        ;pulse
    out    43h,al
    mov    al,byte ptr cs:[frametime]
    out    40h,al
    mov    al,byte ptr cs:[frametime+1]
    out    40h,al
    ret

SetINT8 ENDP

;-----------------------------------------------------------------
; RestoreINT8 - Restores Timer Interrupt (8)
;    IN     : -
;   OUT     : -
;  Modified : ax,dx
;  Vars Used: oldINT8


RestoreINT8 PROC NEAR
    cli
    push    es
    mov    ax,0
    mov    es,ax
    mov    ax,WORD PTR cs:oldINT8[0]
    mov    dx,WORD PTR cs:oldINT8[2]
    mov    es:[8*4],ax
    mov    es:[8*4+2],dx
    sti

    ; retore timer to old setting
    mov    al,34h        ;pulse
    out    43h,al
    mov    al,0
    out    40h,al
    mov    al,0
    out    40h,al
    pop    es
    ret

RestoreINT8 ENDP

;-------------------------------------------------------------------
; DisableKbd - Disables Keyboard
;    IN     : -
;   OUT     : -
;  Modified : ax
;  Vars Used: -

DisableKbd PROC NEAR
    in    al,21h
    or    al,00000010b
    out    21h,al
    ret
DisableKbd ENDP

;-----------------------------------------------------------------
; EnablesKbd - Enables Keyboard
;    IN     : -
;   OUT     : -
;  Modified : ax
;  Vars Used: -

EnableKbd PROC NEAR
    in    al,21h
    and    al,11111101b
    out    21h,al
    ret
EnableKbd ENDP

;-----------------------------------------------------------------

INT9handler PROC FAR
    push    ax
        in      al,60h
       ; cmp     al,01h      ; ESC
       ; je     nokey
    cmp    al,1ch        ; RETURN
    je    nokey
       ; cmp     al,39h      ; SPACE
       ; je     nokey

    ;ignore all other keys
        in      al,61h
        mov     ah,al
        or      al,80h
        out     61h,al
        xchg    ah,al
        out     61h,al
        mov     al,20h
        out     20h,al
        pop     ax
    iret

nokey:
    pop    ax
        jmp     cs:oldint9
INT9handler ENDP

;-----------------------------------------------------------------
; SetINT9 - Sets Keyboard Interrupt (9)
;    IN     : -
;   OUT     : -
;  Modified : ax
;  Vars Used: -

SetINT9 PROC NEAR
    cli
    push    es
    xor    ax,ax
    mov    es,ax
    mov    ax,es:[9*4]
    mov    word ptr cs:oldint9[0],ax
    mov    ax,es:[9*4+2]
    mov    word ptr cs:oldint9[2],ax
    mov    ax,offset INT9handler
    mov    es:[9*4],ax
    mov    es:[9*4+2],cs
    pop    es
    sti
    ret
SetINT9 ENDP

;-----------------------------------------------------------------
; RestoreINT9 - Restores Keyboard Interrupt (9)
;    IN     : -
;   OUT     : -
;  Modified : ax
;  Vars Used: -

RestoreINT9 PROC NEAR
    cli
    push    es
    xor    ax,ax
    mov    es,ax
    mov    ax,word ptr cs:oldint9[0]
    mov    bx,word ptr cs:oldint9[2]
    mov    es:[9*4],ax
    mov    es:[9*4+2],bx
    pop    es
    sti
    ret
RestoreINT9 ENDP

;-----------------------------------------------------------------
; Waitborder - Wait for next VR
;    IN     : -
;   OUT     : -
;  Modified : -
;  Vars Used: -

Waitborder PROC NEAR
    push    ax
    push    dx
    mov    dx,3dah
wbr1:    in    al,dx
    test    al,8
    jnz    wbr1
wbr2:    in    al,dx
    test    al,8
    jz    wbr2
    pop    dx
    pop    ax
    ret
Waitborder ENDP

;-----------------------------------------------------------------
; GetRasterline - Gets current rasterline (not exact!) apprx range:1..479
;    IN     : -
;   OUT     : ax    (Rasterline)
;  Modified : cx,dx
;  Vars Used: frametime

GetRasterline PROC NEAR
    ;AX=scan line the VGA is in (requires ints set)
    cli
    xor    al,al
    out    43h,al
    in    al,40h
    mov    dl,al
    in    al,40h
    mov    dh,al

    mov    ax,cs:frametime
    sub    ax,dx
    mov    cx,506
    mul    cx
    mov    cx,cs:frametime
    div    cx
    sub    ax,26        ;adjust to 480 (506-26=480)

    sti
    ret
GetRasterline ENDP

;-----------------------------------------------------------------
; WaitRasterline - Wait until Rasterline (not exact!) apprx. range 1..479
;    IN     : dx    (Rasterline)
;   OUT     : -
;  Modified : ax,cx,dx
;  Vars Used: frametime

WaitRasterline PROC NEAR
    ;returns when Scan Line=DX (requires ints set)
    cli
    mov    cx,506          ;# of horizontal scan lines + VR
    mov    ax,480          ;# of horizontal scan lines
    sub    ax,dx
    mul    word ptr cs:frametime
    div    cx
    mov    cx,ax

waitraster1:
    xor    al,al
    out    43h,al
    in    al,40h
    mov    ah,al
    in    al,40h
    xchg    al,ah
    cmp    ax,cx
    ja    waitraster1

    sti

    ret
WaitRasterline ENDP
;-----------------------------------------------------------------