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

   1 ;
   2 ; 2016-02-28, Groepaz
   3 ; 2017-06-15, Greg King
   4 ;
   5 ; unsigned char cpeekrevers (void);
   6 ;
   7
   8         .export         _cpeekrevers
   9
  10 ; Get a system-specific file.
  11 ; Note:  The cbm610, and c128 targets need special
  12 ; versions that handle RAM banking and the 80-column VDC.
  13
  14 .if     .def(__C16__)
  15         .include        "plus4.inc"     ; both C16 and Plus4
  16 .elseif .def(__C64__)
  17         .include        "c64.inc"
  18 .elseif .def(__CBM510__)
  19         .import         CURS_X: zp, SCREEN_PTR: zp
  20         .include        "cbm510.inc"
  21 .elseif .def(__PET__)
  22         .include        "pet.inc"
  23 .elseif .def(__VIC20__)
  24         .include        "vic20.inc"
  25 .endif
  26
  27
  28 _cpeekrevers:
  29         ldy     CURS_X
  30         lda     (SCREEN_PTR),y  ; get screen code
  31         and     #$80            ; get reverse bit
  32         asl     a
  33         tax                     ; ldx #>$0000
  34         rol     a               ; return boolean value
  35         rts