git.sur5r.net Git - cc65/blob - libsrc/atari/cclear.s

   1 ;
   2 ; Ullrich von Bassewitz, 08.08.1998
   3 ;
   4 ; void cclearxy (unsigned char x, unsigned char y, unsigned char length);
   5 ; void cclear (unsigned char length);
   6 ;
   7
   8         .export         _cclearxy, _cclear
   9         .import         popa, _gotoxy, cputdirect
  10         .importzp       tmp1
  11
  12 _cclearxy:
  13         pha                     ; Save the length
  14         jsr     popa            ; Get y
  15         jsr     _gotoxy         ; Call this one, will pop params
  16         pla                     ; Restore the length and run into _cclear
  17
  18 _cclear:
  19         cmp     #0              ; Is the length zero?
  20         beq     L9              ; Jump if done
  21         sta     tmp1
  22 .ifdef DIRECT_SCREEN
  23 L1:     lda     #0              ; Blank - screen code
  24 .else
  25 L1:     lda     #$20            ; Blank
  26 .endif
  27         jsr     cputdirect      ; Direct output
  28         dec     tmp1
  29         bne     L1
  30 L9:     rts
  31
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