A font with hundreds or thousands of characters must be handled differently from
a font containing the ASCII set of up to 256 characters. In addition to using more
complicated techniques for searching the file, the program needs a way to represent
characters with two-byte codes as well as one-byte codes. Both situations are addressed
by the use of special codes at the beginning of a Big Font file.

The first line of a Big Font shape definition file must be as follows:

*BIGFONT nchars,nranges,b1,e1,b2,e2,...

nchars represents the approximate number of character definitions in the set; if it is off
by more than about 10 percent, either speed or file size suffers. You can use the
rest of the line to name special character codes (escape codes) that signify the start
of a two-byte code. For example, on Japanese computers, Kanji characters start with
hexadecimal codes in the range 90-AF or E0-FF. When the operating system sees one
of these codes, it reads the next byte and combines the two bytes into a code for
one Kanji character. In the *BIGFONT line, nranges tells how many contiguous ranges of numbers are used as escape codes; b1 , e1 , b2 , e2 , and so on, define the beginning and ending codes in each range. Therefore, the header
for a Japanese Big Font file might look like this:

*BIGFONT 4000,2,090,0AF,0E0,0FF

After the *BIGFONT line, the font definition is just like a regular text font, except that character
codes (shape numbers) can have values up to 65535.