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Text File  |  1979-12-31  |  2KB  |  38 lines
  1. procedure Inverse;
  2.  
  3. { Procedure to restore Inverse characters
  4.              to the PCG.
  5.  
  6.   This procedure is derived from the disk
  7.   ROM routine at  E02AH,  which fills the
  8.   PCG  with  inverse  characters  of  the
  9.   current font type.
  10. }
  11.  
  12. begin { Inverse }
  13.  
  14.  
  15.  
  16.                           { SCNTOP        EQU        0F000H  }
  17.                           { PCGRAM        EQU        0F800H  }
  18.                           { ROMPORT       EQU        0BH     }
  19.  
  20.                           { INVERSE:                         }
  21. inline($3E/ $01/          {          LD      A,1             }
  22.        $D3/ $0B/          {          OUT     (ROMPORT),A     }
  23.        $21/ $F000/        {          LD      HL,SCNTOP       }
  24.        $11/ $F800/        {          LD      DE,PCGRAM       }
  25.                           { INV_1:                           }
  26.        $7E/               {          LD      A,(HL)          }
  27.        $2F/               {          CPL                     }
  28.        $12/               {          LD      (DE),A          }
  29.        $23/               {          INC     HL              }
  30.        $13/               {          INC     DE              }
  31.        $CB/ $5C/          {          BIT     3,H             }
  32.        $28/ $F7/          {          JR      Z,INV_1         }
  33.        $AF/               {          XOR     A               }
  34.        $D3/ $0B           {          OUT     (ROMPORT),A     }
  35.       )
  36.  
  37. end; { Inverse }
  38.