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; Copyright (c) 1999 Greg Haerr <greg@censoft.com>

;

; int10 bios video function access

; int16 bios keyboard access

;

; assembly language routines for MSDOS Microsoft C v5.10

;

; assemble with masm -Mx -D__MEDIUM__

;

MSC = 1

;__MEDIUM__ = 1

        include asm.h

        .header

        .cseg

;

; es:bp = int10(int ax,int bx)

;       Call video bios using interrupt 10h

;

        .cproc  int10

        push    bp

        mov     bp,sp

        push    es

        push    ds

        push    si

        push    di

        mov     ax,arg1[bp]     ; get first arg

        mov     bx,arg1+2[bp]   ; get second arg

        int     10h

        mov     dx,es           ; return es:bp

        mov     ax,bp

        pop     di

        pop     si

        pop     ds

        pop     es

        pop     bp

        ret

        .cendp  int10

;

; int kbpoll(void) - poll keyboard for char ready

;

        .cproc  kbpoll

        mov     ah,01h                  ; read, no remove

        int     16h

        jz      $9                      ; no chars ready

        mov     ax,1                    ; chars ready

        ret

$9:     xor     ax,ax                   ; no chars ready

        ret

        .cendp  kbpoll

;

; int kbread(void) - wait and read a kbd char when ready

;

        .cproc  kbread

        mov     ah,00h                  ; read and remove

        int     16h                     ; return ax

        ret

        .cendp  kbread

;

; int kbflags(void) - return kbd shift status

;

        .cproc  kbflags

        mov     ah,02h                  ; get shift status

        int     16h

        mov     ah,0                     ; low bits only for now...

        ret

        .cendp  kbflags

        .cend

        end