RTEMS 3.2.1 is provided for historical interest only.  It is no longer
the supported RTEMS Ada solution.  The preferred solution is to use
the C implementation of RTEMS as a run-time for GNAT.  To encourage this
OAR Corporation provides GNU/Linux RPMs for GNAT/RTEMS as well as making
all source code and patches available.

To provide some historical perspective, the Ada implementation of RTEMS
was conceived as an open source alternative to the Ada83 run-time.  In
those dark days of yesteryear, it was often painful to integrate the 
the compiled libraries of C implementation with Ada code.  Ada compilers
did not include C compilers so one was faced with multiple toolsets,
only marginally compatible object formats, and sometimes radically
different use of memory.  We wanted to provide the functionality of
a traditional RTOS to Ada83 programmers.  Having an Ada implementation
of RTEMS that was algorithmically and structurally equivalent to the
C implementation was our solution. 

RTEMS 3.2.1 is the last release which had both a C and an Ada implementation.
After that, we implemented POSIX threads in RTEMS in order to facilitate
porting GNAT.  This was all long enough ago that we did initial testing
of GNAT with a version that had no tasking and used it to compile the Ada
implementation.  Even at that early date (2.0x), it produced code that
was frequently superior to that of other Ada compilers.

The Ada implementation lives on today in the form of the Ada binding to
the Classic API and the associated test suite.

The RTEMS Project was started to address the run-time requirements of
embedded real-time Ada applications.  We continue to work today 
toward that goal even when our effort is strictly as volunteers and
Ada proponents.

Joel Sherrill
Director of Research and Development


NOTES:

1.  This release was cut on August 15, 1995.  At that point, there had
    had already been a number of RTEMS releases and submissions from
    users.

2.  You can not order tapes or old documentation from OAR Corporation or
    the U.S. Army.  So don't even try.  Besides, they were QIC-150 tapes.
    Do you really want one anyway?

3.  OAR Corporation has moved since this release was made.  Please 
    see our contact information at http://www.oarcorp.com for
    the current information.

4.  The official distribution site for RTEMS is http://www.oarcorp.com.
    http://www.rtems.army.mil seems to still be around but has not
    been updated since version 3.6.0.