Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!swrinde!zaphod.mps.ohio-state.edu!mips!daver!lynx!mike
From: mike@lynx.uucp (Mike Bunnell)
Newsgroups: comp.realtime
Subject: Re: Realtime Unix?
Keywords: time critical applications
Message-ID: <7110@lynx.UUCP>
Date: 1 Mar 90 19:40:31 GMT
References: <2057@hydra.riacs.edu> <1990Feb28.163109.17440@me.toronto.edu>
Reply-To: mike@lynx.UUCP (Mike Bunnell)
Organization: Lynx Real-Time Systems Inc, Campbell CA
Lines: 19

>
>[...
>It also appears that NASA will be using a realtime UNIX system (i.e. LYNX OS
>- a Sys V R 3.2 derivative with BSD features) for use on the space station
>(for whenever it comes into being). 
>..]
>

Thank you for mentioning LynxOS.  LynxOS is NOT, however, a derivative
of SYS VR3 (yuck) or any other operating system.  LynxOS was written
from scratch as an operating system for running hard real-time applications.
Actually, we origionally chose the Berekely 4.2 system call interface
(working signals, select, symbolic links, sockets, job control,
long file names etc.)
System V compatiblity was added later as were 4.3 stuff and POSIX.
It is true that you can run System V executables, but that is because
everyone has picked System V for there binary coding standards and
there is more off-the-shelf software available for system V.
However when we compile GNU stuff or X-Windows we make the BSD versions.