byte is the type identifier for a built-in 8 bit ordinal type, whose values are the integers between 0 and 255 (maxbyte).
Below is a simple program that writes all possible values of byte to a file.
program bytes;
var
f : file of byte;
b : byte;
begin
rewrite(f, 'bytes.dat');
for b := 0 to maxbyte do
write(f, b)
end.
Operating Systems: All
Standard Pascal: No