CLEARS.I

[Table of Contents]

The CLEARS.I include file resides on the Kyan Pascal 2.x Utilities Disk 1. It contains the following four procedures:

• PROCEDURE Clear_to_EOLn
• PROCEDURE Clear_Screen;
• PROCEDURE Clear_to_EOP;
• PROCEDURE Clear_Ln_at(Y: Integer);

Source Code

PROCEDURE Clear_to_EOLn;

   VAR

       CURRENT,Cursor_Pos:Integer;

   BEGIN

#A

  LDY #5     ;offset to Cursor_Position

  LDA $55    ;get COLCRS (85)

  STA (_SP),Y;...store it

  INY        ;offset to MSB

  LDA #$00   ;zero out

  STA (_SP),Y;the MSB

#

       FOR CURRENT:=Cursor_Pos TO 39 DO

           WRITE(CHR(254));

END;(* Clear_to_End *)

PROCEDURE Clear_Screen;

   BEGIN

       WRITE(CHR(125));

END;(* Clear_Screen *)

PROCEDURE Clear_to_EOP;

   VAR

       Cl_Line,Cl_P :INTEGER;

       RowCrs,ColCrs:Integer;

   BEGIN

#A

  LDY #7      ;offset to RowCrs

  LDA $54     ;...get ROWCRS (84)

  STA (_SP),Y ;...store in RowCrs

  LDY #5      ;offset to ColCrs

  LDA $55     ;...get COLCRS (85) LSB

  STA (_SP),Y ;...store in ColCrs

#

       FOR Cl_Line:= ColCrs TO 39 DO

           WRITE(CHR(254));

       WRITELN;

       FOR Cl_P:=23 DOWNTO RowCrs+1 DO

           WRITE(CHR(156));

END;(* Clear_to_EoP *)

PROCEDURE Clear_Ln_at(Y: Integer);

    BEGIN

#A

  LDA $54     ;get value in ROWCRS (84)

  STA _T      ;...store LSB for later

  LDY #5      ;offset to Y

  LDA (_SP),Y ;...get Y value

  STA $54     ;...store in ROWCRS

#

        WRITE(CHR(156));

#A

  LDA _T      ;get old row number

  STA $54     ;restore cursor position

#

END;(* Clear_Ln_at *)