The Borland CHR Font File Format

Original Documentation

The CHR files are scalable fonts used by the Borland graphics interface
(BGI) to display fonts in graphics mode.
OFFSET              Count TYPE   Description
0000h                   4 char   ID='PK',08,08
0004h                   4 char   ID='BGI '
0008h                   ? char   Font description, terminated with #26
0008h                   1 word   Headersize
+????                            ="SIZ"
                        4 char   Internal font name
                        1 word   Font file size in bytes
                        1 byte   Font driver major version
                        1 byte   Font driver minor version
                        1 word   0100h
                    "SIZ" word   Zeroes to pad out the header
0080h                   1 char   Signature byte, '+' means stroke font
0081h                   1 word   Number of chars in font file
                                 ="NUM"
0083h                   1 byte   undefined
0084h                   1 byte   ASCII value of first char in file
0085h                   1 word   Offset to stroke definitions
0087h                   1 byte   Scan flag ??
0088h                   1 byte   Distance from origin to top of capital
0089h                   1 byte   Distance from origin to baseline
008Ah                   1 byte   Distance from origin to bottom descender
008Bh                   4 char   Four character name of font
0090h               "NUM" word   Offsets to character definitions
0090h+              "NUM" byte   Width table for the characters
"NUM"*2
0090h+                           Start of character definitions
"NUM"*3

The individual character definitions consist of a variable number of words
describing the operations required to render a character. Each word
consists of an (x,y) coordinate pair and a two-bit opcode, encoded as shown
here:

Byte 1          7   6   5   4   3   2   1   0     bit #
               op1  <seven bit signed X coord>

Byte 2          7   6   5   4   3   2   1   0     bit #
               op2  <seven bit signed Y coord>

          Opcodes

        op1=0  op2=0  End of character definition.
        op1=0  op2=1  Do scan
        op1=1  op2=0  Move the pointer to (x,y)
        op1=1  op2=1  Draw from current pointer to (x,y)

EXTENSION:CHR
OCCURENCES:PC
PROGRAMS:Borland Pascal, Borland C
REFERENCE:BGIKIT.ZIP
SEE ALSO:
VALIDATION:
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