type ByteCard = Cardinal attribute (Size = BitSizeOf (Byte));
ByteCard is an unsigned integer type which is one “unit” wide. On most platforms one unit has 8 bits, therefore the type is prefixed “byte-” and usually has a range of 0 .. 255.
ByteCard in GNU Pascal is compatible to unsigned char in GNU C.
There are lots of other integer types in GPC, see Integer Types.
ByteCard is a GNU Pascal extension.
program ByteCardDemo; var a: ByteCard; begin a := 42; WriteLn (a) end.