;*** writes some data to trk 0, sector 0, side 0 of floppy disk
;*** uses int 13h

Title   DISKWR.ASM
Page    60,132

stk     segment stack                ; set up a stack
        dw      64 dup(?)
stk     ends

data    segment
buf     db      '01234abcdefg'
        db      500 dup('$')
data    ends

code    segment
        assume  ds:data, cs:code
main    proc    far     
        mov     ax,data         ; Bookkeeping...
        mov     ds,ax
        mov     es,ax
        
        mov     cx,0a0ah        ; track 10, sector 10
        mov     al,1            ; 1 sector
        mov     ah,3            ; write sector command
        mov     dh,0            ; side 0
        mov     dl,0            ; drive A
        mov     bx,offset buf   ; address of write buffer
        int     13h             ; write it

        mov     ax,4c00h                          ; Return to DOS
        int     21h
main    endp         
code    ends
        end     main