Thoughts needed

[Barnacle Wes]

In article <4144 at orstcs.CS.ORST.EDU>, kean at mist.cs.orst.edu (Kean Stump) writes:
> 
> I need recommendations for a multi-user multi-tasking os that will run
> on the following equipment:
> 	
>	I have a Compaq 386/20 with 5 meg ram 
	[ all sorts of goodies deleted ]
> 
> I'm also considering Concurrent-Dos and PC-MOS/386 as runners-up.
> One of the major requirements is that real-time sampling on the order
> of 10K samples/sec (~40 bytes/sample) needs to be possible (the Compaq
> will spend some time on a chunk of ice in the Arctic next spring
> collecting data from a variety of instruments dropped through a hole in
> the ice) and a good C and FORTRAN (8-<) compiler are needed.

Hmmm... Have you carefully though this out?  A Unix (or unix-like)
system is probably not your best bet for doing data acquisition on.
Unix was designed from the beginning to be a time-share system, not a
real-time system.

If you really need to acquire data at this rate, you will be better
off sticking with good ol' boneheaded MS-DOS, where you won't have to
worry about another user, or something in the crontab, blowing your
data acquisition away.

There are several good compilers available.  High-C 386 is a screamer,
and supports the 387.  MicroWay sells C and Fortran compilers that
generate 386 code, and support either the 387 or the Weitek.

Have you thought about where you are going to store 400K/sec of data?
Most hard disks will not run at that rate consistently, and definitely
not if any head seeking is going on.  I don't know if cartridge tape
drives are fast enough, either.  You may end up looking for a FAST
9-track system just to be able to store the data!  That is what I've
settled on at work, but some of our daq requirements are even tighter
than yours.
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