Re: Real time?

[Jon Elson <jmelson-at-artsci.wustl.edu>]

Ian Wright wrote:

> Hi,
>
> I've just been looking at the www.qnx.com site and playing with their demo
> program. I don't know whether this is something you are aware of or whether
> it may be relevant but the company claims their program QNX, is a real-time
> OS suitable for machine control applications. It seems to be based on a
> Unix-like OS and the demo which fits on a single floppy has a micro-kernel
> of 45Kb and all the gubbins to run a web browser and server, network stuff,
> html writer and has several demo web pages! It doesn't look like the full
> program is out yet but it says it will be free for private use. I just
> wondered if EMC could be persuaded to work with this in which case it could
> probably be incorporated into very simple equipment integrated into the tool
> itself.

QNX has been around since the 68000 CPU was created, back in the late
80's.  I'm sure it has gotten new features and such, but it is still aimed at
a somewhat different kind of use.

Yes, EMC could be converted.  I would take a rough guess at about 1000
man-hours of work for one of the developers at NIST to do this.  Probably
10000 Hours for one of us!  QNX is a commercial software package, and
you have to buy it to develop software for it.  You may be able to run
pre-compiled code on the free one, but I don't think you can do any more
without a license.  QNX is not very expensive, but I think you DO need a
license for every machine.  Maybe they are changing that plan.

EMC will run on a small system.  I am pretty sure it could be set up to
load from a modest flash memory card.  There are PC-104 systems
that run from a deck-of-cards size to 2 or 3 times that size, which is
still DARN small!  These systems often cost more than a desktop PC,
just as a laptop costs more.

You can also make some very small systems with desktop parts.  A micro
disk drive, ATX motherboard and interface cards really don't take up
much space.

Jon