Re: Re[1]: Appropriate WinNT Files

[JohnDRoc-at-aol.com]

I may have to duck and hide for this one, but...

To say it flat out "won't" work is not entirely true.  I've done alot of 
research on porting EMC to NT.  There are many issues involved.  EMC was 
designed to run on a real-time operating system - what made Linux a good 
candidate, as opposed to something like VXWorks, was price and resolution.  
(Check out previous list postings for discussions on timing resolution.)  The 
biggest challenge is accessing the STG card in NT, which would (most likely) 
have to be done through a hardware driver.  I played around with the sample 
driver that STG created and even came up with a small machine controller 
program based on a program that JRKerr offers for their PIC Servo boards and 
hacking in commands to access the STG driver (written in C++ Builder).  It 
was pretty slick (and rudimentary) - I was able to get a servo motor running 
with it.  My thought was to incorporate the EMC motion controller code in a 
driver similar to the STG sample driver.  The problem I ran into there is 
that low-level system drivers cannot perform 
floating point operations (EMC has floating point operations).  I had many a 
discussion with Don Mclane (STG) regarding the latency issues - some of the 
tests that he ran using the STG's hardware interrupt indicated that it may 
not be a serious issue, even without the real time add-ons.  The ISR needs to 
be set as a (very) high priority thread.  The resolution issue is still 
there, though.  Anyway, to make a short story long, that's as far as I got.  
After several slooooow months, I had to break down and get a "real" job.  I 
have since downloaded the MS DDK with the greatest intentions of continuing, 
but after staring at a computer screen, at work, for 8 hrs a day, I find my 
ambition wanes drastically, when I get home.  It's a very ambitious 
undertaking, difficult but not impossible.

-John