127 lines
2.2 KiB
Plaintext
127 lines
2.2 KiB
Plaintext
{
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binary.pas contains procedures and functions for dealing
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with binary data.
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}
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type
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BStr = String[2]; { String representing a u8. }
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WStr = String[4]; { String representing a u16. }
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BinFile = File of Byte;
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Procedure ExpandFile(var fil : BinFile; var pos : Integer; pad : Integer);
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var
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i : Integer;
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begin
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for i := 1 to pad do Write(fil, Byte(0));
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pos := FilePos(fil);
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end;
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function ValidHexDigit(bval: Byte): Boolean;
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var
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IsValid : Boolean;
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begin
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IsValid := False;
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if ((bval >= $30) and (bval <= $39)) then
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IsValid := True;
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if ((bval >= $41) and (bval <= $46)) then
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IsValid := True;
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if ((bval >= $61) and (bval <= $66)) then
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IsValid := True;
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ValidHexDigit := IsValid;
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end;
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function ReadDigit(bchr: Char): Byte;
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var
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bval : Byte;
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label
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exitearly;
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begin
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bval := Byte(bchr);
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if (not ValidHexDigit(bval)) then
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begin
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bval := 0;
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goto exitearly;
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end;
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{Normalize downcase digits to upcase digits.}
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if (bchr >= 'a') then
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bval := bval xor $20;
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{Perform the conversion.}
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if (bchr >= 'A') then
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bval := bval - $37
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else
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bval := bval - $30;
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exitearly:
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ReadDigit := bval;
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end;
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function ReadByte(bstr : BStr): Byte;
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var
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out : Byte;
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begin
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out := ReadDigit(bstr[1]) shl 4;
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out := out + ReadDigit(bstr[2]);
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ReadByte := out;
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end;
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function ReadWord(bstr : WStr): Integer;
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var
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out : Integer;
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I : Integer;
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begin
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out := 0;
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for I := 1 to 4 do
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begin
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out := out shl 4;
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out := out + Integer(ReadDigit(bstr[I]));
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end;
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ReadWord := out;
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end;
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function ToDigit(digit : Byte): Char;
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var
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c : Char;
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begin
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c := Char(0);
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if (digit < $0A) then
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c := Char(digit + $30)
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else if (digit <= $0F) then
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c := Char(digit + $37);
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ToDigit := c;
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end;
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function WriteByte(bval : Byte): BStr;
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var
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s : BStr;
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begin
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s := '00';
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s[1] := ToDigit(bval shr 4);
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s[2] := ToDigit(bval and $0F);
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WriteByte := s;
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end;
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function WriteWord(bval : Integer): WStr;
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var
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s : WStr;
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begin
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s := '0000';
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s[1] := ToDigit((bval shr $0C) and $000F);
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s[2] := ToDigit((bval shr $08) and $000F);
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s[3] := ToDigit((bval shr $04) and $000F);
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s[4] := ToDigit(bval and $000F);
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WriteWord := s;
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end;
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