Implementing an Entire System

[sampson@cod.nosc.mil (Charles H. Sampson)]

     Does anyone have any experience with implementing an entire system in
Ada?  By this I mean using Ada to write the system's executive, then writing
the non-executive (user, task state, etc.) part in Ada to get its executive
services from that executive rather than from the executive supplied as part
of the Ada compiling system.  I need to know lessons learned.  Citations are
acceptable.

     I know this is quite close to an Ada heresy, but it's a very real is-
sue on a project I'm working on, for a variety of technical reasons.

     I read this news group regularly, but email should probably be used
unless the response is of general interest.

                                Charlie