Re[4]: emc on microway alpha pc?

["Terry L. Ridder" <terrylr-at-blauedonau.com>]

hello matt;

thank you for writing that.

i have been sitting to long at the computer
and typing too much and the left arm is killing me.
i was trying to cut down on typing and keep my
postings still readable.

On Thu, 12 Oct 2000, Matt Shaver wrote:

jon> From: Jon Elson <jmelson-at-artsci.wustl.edu>

terrylr> "Terry L. Ridder" wrote:
terrylr>  in talking with matt shaver concerning intel hardware
terrylr>  limiting the ability of emc to drive steppers currently
terrylr>  i was thinking of trying the alpha since the hardware
terrylr>  is a little different and should not be the limiting
terrylr>  factor. matt, sent me an excel spreadsheet which showed
terrylr>  the limits under intel hardware.
terrylr

jon> Hmmm, I'd like to see that.

matt>
matt> Sure! It's at:
matt>
matt> http://users.erols.com/mshaver/stepfreq.xls
matt>
matt> As far as the ISA bus, parallel ports,
matt> and step pulse output goes, I don't
matt> think that ISA port are too slow for
matt> step and direction output. The problem
matt> with ISA was that the 8254 is on the ISA
matt> bus and reprogramming the interrupt rate
matt> takes too long (like 10uS I think), so
matt> we couldn't schedule pulse outputs by
matt> using the 8254 in one-shot mode.
matt> That forced us into periodic mode and smack
matt> into the granularity problem. On the other hand,
matt> who knows what cool timing hardware lurks inside
matt> Terry's Alpha? And for that matter, has
matt> RTlinux been ported to that platform in a way
matt> that takes advantage of the (possibly) better
matt> hardware?
matt>
matt> Matt
matt>

-- 
Terry L. Ridder

digging deep, i feel my conscience burn
i need to know who and what i am
this hunger jolts me from complacency
rocks me, makes me meet myself
----kendall payne---closer to myself---