Re: Quality systems (Was: Using Ada for device drivers? (Was: the Ada mandate, and why it collapsed and died))

[Richard Riehle <richard@adaworks.com>]

David Lightstone wrote:

> If I am to believe the documentation for the Meridian compilier version 4.1
> it should work on a 8086
> with MS-DOS version 2.1 or later

Correct.  Beyond that, Meridian had a compiler that worked
on the MacIntosh.   It also  worked on later versions of MS-DOS
with x386.   It included a nice set of packages in its DOS Library
for doing screen formatting, etc.   There were two drawbacks to
the Meridian compiler that would have been fixed if it Rational had
allowed it to survive the transition to Ada.  One was the definition
for System.Address which was a signed integer and made it
impossible to access the high-order memory beyond 640K. The
other was the absence of a Mouse library.

Aside from that, the Meridian compiler was fun.   There was also
the Janus compiler.  It didn't have as many libraries, but accessing
low-level aspects of the environment was a little easier so one
could build one's own libraries.

The Alsys compiler was  quite good but priced too high.  They
could have priced it more competitively and made a real
difference.  Of particular usefulness was the ability to access
any part of memory with the Alsys compiler and the availability
of an Unsigned_Number package.

Richard Riehle