On Thu, 30 Sep 1999, Steve Ashcraft wrote:
> serious problem is the variation of the latency in the computer. This is a
> factor of both the hardware (which is probably not a problem) and the
> software that responds to the interrupt. I'd love to hear some opinions
> about how DOS handles interrupts and if there is a problem there that is
Sitting out here in the cheap seats (its been quite some time since I
played with DOS and any sorta realtime stuff), I can't see how what DOS
does or doesn't do would really matter, since you're gonna go in and
juggle around the interrupt mask and clock interrupt frequency anyway (or
at least I would).
In terms of the archetecture of a good system, I would think you could
combine what everyone's been saying by creating a single board computer
running a custom kernal (and DOS when its not?) with a few switches and
leds. That box would be resposible for keeping accurate time and
extremely basic functionality in terms of stand alone operation (one car
at a time, show the time, whatever). Then have that box talk to a user
interface computer running win32 stuff. Have that computer keep track of
the data, deal with multiple cars on course, etc. etc. etc.
Having said all that, I'm sure I could build a really kickass system for
$10k (single board computer & misc crap for $2k, laptop for $2k, misc
hardware, profit, etc.)... Which is probably 10x what people wanna pay for
I'd be interested to know what system architectures and designs folks out
there really end up using for timing systems.