Note: The HOLD III Ada compiler is superseded
by M68K Ada.
The HOLD III Ada 95 compiler was developed for
the High Order Language Demonstration (HOLD) program run by
Lucas Aerospace and part
funded by the UK Ministry of Defence. It is based on the GNU C compiler from
the Free Software Foundation and includes
the validated GNAT Ada 95 front end from New York University.
The application domain is safety-critical embedded computers such as the
Lucas Full Authority Digital Engine Controller (FADEC) used on Rolls Royce
RB199 engines. This is the first time that a GCC-based Ada compiler has
been used for embedded applications that require such a high level of
correctness, and the HOLD III program has been an ideal way of demonstrating
that this can be done.
Being delivered in November 1996, HOLD III Ada 95 was also the first Ada
95 compiler for the Motorola M68000 family, and continues to be the
only compiler targeted to the 68020 that is suitable for safety-critical
The compiler supports a subset of Ada 95 that is defined by the
restrictions in Annex H of the Ada 95 Language Reference Manual. This subset
is similar to the SPARK subset used to write the HOLD III source code.