Re: Real time?

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

Ian Wright wrote:

> Hi Jon,
>
> I'm sure you are right, it was my first contact with QNX. What impressed me
> though was their ability to compact all the stuff onto one floppy, including
> web browser, server, editor, file manager and even a game! This got me
> thinking that, if they can do all this, why are we having to download
> massive files every time EMC is updated and also having to run large hard
> disks to hold what must, largely, be unnecessary program stuff - all of
> which will inevitably slow down the computer.

Well, a large part of the reason is that most EMC distribution is in source
form, and has a number of large options, variants, test programs, etc. that
are all bundled together.  I'm not even sure the ill-fated Java libraries have
been cut out, although the Java GUI was not very successful.

And, of course, if you are going to compile and link EMC on your machine,
you need all the compilers and object libraries of the Program Development
tools.  And, since I do some debugging and tinkering with things, I want to
have the help libraries and manual pages online, too.  It just keeps adding
more stuff.

> So, it was really their
> 'dynamic HTML' which caught my eye and I wondered whether there could be a
> way there of saving space and, presumably, program operation time by using
> html and java with a minimal browser as they have to run the game, rather
> than several megabytes of Tcl/Tk and scripts to do what, I assume, is a
> similar job. Do you know whether QNX is actually some type of Linux or is it
> something entirely different - its file structure certainly looks
> linux-like.

Umm, as I mentioned, the Java GUI was not a success.  It was quite slow, and
there were many problems with it.  I have never run the Java GUI on my
machine.  I have used the XEMC and now the Tk/Tcl GUI, and they work
quite well.

QNX predates Linux by at least 10-15 years!  It was originally a derivative
of the Unix kernel, with everything unbundled, so you could include only the
things you needed.  If you wanted to take a chunk of Unix C code and put
it in a box on a network (like maybe an ATM, or a device to take data
from electronic time clocks and feed it to a network server to make time sheets)

this is the kind of thing QNX was made for.  Embedded Applications, they call
it.

Of course QNX's file structure looks like Linux, as does all other Unix
derived systems.

Jon