Real time unix?

[David F. Carlson]

In article <26266 at adm.brl.mil>, m14167 at mwvm.mitre.org (Larry Lawrence) writes:
> gregk at cbnewsm.att.com (Gregory Kochanski) inquired on 30 Jan about
> the existence of real time unix that can read/write in 50 micro sec.
> 
> According to an article (Comm. ACM Dec. 1990, vol 33, no 12, "Acquisition
> at Mission Control" by Muratore et al), there is a product called (surprise!)
> "Real-Time Unix" (RTU)(TM) by Concurrent Corporation.  The authors don't
> state how "real time" it is, but describe their use of it for acquiring
> weather data during shuttle landings.
> 
> Let me know if this is useful. If anyone else has experience with RTU
> or equivalent products I would like to know how it works.  Call
> at 703 883-6661, or email.  I am at MITRE Corp., McLean VA.
*

(Larry I tried to call but...)

Concurrent's RTU (Real Time UNIX) is Real UNIX.  It supports full SVID
and is SVVS complient.  It allows realtime priorities and schedulers
in addition to normal timesharing.  It is fully symmetric multiprocessing
and it allows processors to be dedicated to a particular task or set of tasks.
UNIX system calls are modified to be pre-emptible so that a high priority 
process can run as soon as possible.

To the programmer, its primary difference to regular ol' UNIX is that it
has system calls to dedicate resources (CPU, memory, I/O) to the user process.
Thus, when a realtime task *has* to run, it can secure the resources necessary
to complete its task.

RTU currently runs on Motorola 68020/030/040 and MIPS R3000 in configuations
of 1, 2, 4 and 8 CPUs.  Tightly integrated multi-threaded device drivers
for vector accellerators, disk I/O and data acquisition are available.

-- 
David F. Carlson, Concurrent Computer Co.
dave at bigguy.ocpt.ccur.com       Fairport, NY

"The faster I go, the behinder I get." --Lewis Carroll