.include #16bit
   .include #system
   
sd_secs:
   dey                        ; ought to be at least one sector
   tya                        ; save it on stack
   pha
   jsr   dskinv               ; do disk io (assume everything else's setup)
   bmi   :xover               ; leave on errors
   pla                        ; get sectors left
   beq   :over                ; 0 = done->
   
   tay                        ; get no in Y
   adc8.w $80,dbuflo          ; add #$80 to buffer count
   inc   daux1                ; wanna next sector ?
   bne   sd_secs              ; sure !
   inc   daux2 
   bne   sd_secs

:xover
   pla
   ldy   #$FF
:over
   rts