git.sur5r.net Git - cc65/blob - libsrc/cbm/diskinit.s

   1 ;
   2 ; Oliver Schmidt, 2012-10-17
   3 ;
   4
   5         .export         diskinit
   6         .import         opencmdchannel, closecmdchannel
   7         .import         writefndiskcmd, readdiskerror
   8         .import         isdisk, fnunit, fncmd
   9
  10 ;------------------------------------------------------------------------------
  11 ; diskinit
  12
  13 .proc   diskinit
  14
  15 ; Save device
  16
  17         sta     fnunit
  18
  19 ; Check for disk device
  20
  21         tax
  22         jsr     isdisk
  23         bcc     open
  24         lda     #9              ; "Illegal device"
  25         rts
  26
  27 ; Open channel
  28
  29 open:   jsr     opencmdchannel
  30         bne     done
  31
  32 ; Write command
  33
  34         lda     #'i'            ; Init command
  35         sta     fncmd
  36         jsr     writefndiskcmd
  37         bne     close
  38
  39 ; Read error
  40
  41         ldx     fnunit
  42         jsr     readdiskerror
  43
  44 ; Close channel
  45
  46 close:  pha
  47         ldx     fnunit
  48         jsr     closecmdchannel
  49         pla
  50
  51 done:   rts
  52
  53 .endproc