VMS Help PASCAL, Data Types, Ordinal, UNSIGNED Types  *Conan The Librarian (sorry for the slow response - running on an old VAX)

  Compaq Pascal provides the UNSIGNED and  UNSIGNED64  types  (not
  available  on  all  systems).   Also provided are the UNSIGNED8,
  UNSIGNED16, UNSIGNED32,  CARDINAL,  CARDINAL16,  and  CARDINAL32
  types,  which  are  used as synonyms for the UNSIGNED type.  The
  range of unsigned values consists of nonnegative integer values.

  The  largest  possible  value  of  the  UNSIGNED  data  type  is
  represented by the predefined constant MAXUNSIGNED.

  The largest value for the UNSIGNED64 data type is represented by
  the predefined constant MAXUNSIGNED64.

  The smallest possible value for the UNSIGNED data type is 0.