Re[3]: emc on microway alpha pc?

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

hello;

allow me to but this in simple terms.

all i am trying to do is get the most stable
performance for both the bridgeport, rtlinux,
and emc using the equipment i have on hand or
that i can obtain for the least possible expense
right now.

i do understand the numerous limiting factors
and trade-offs. i have talked with matt shaver
at length concerning the work that jon is doing.
i understand why jon is doing it.

i want to see what i can get going now, not next month
not two months from now, but now.

On Thu, 12 Oct 2000, Jon Elson wrote:

<snip>
jon> 
jon> I don't know what sort of pulse resolution you are trying for.
jon> I guess somewhere in the 50 uS granularity might be reasonable
jon> (that's 20,000 interrupts/second from the timer).  Depending on
jon> the RT overhead for the context switch and interrupt, it might
jon> be possible to go faster.
jon> 
jon> Yes, I guess that a 1 uS cycle time for an ISA parallel
jon> port is pretty small compared to those rates.
jon> 
jon> I am working on a step pulse generator chip that would connect to the
jon> parallel port, and drive 4 steppers, with pulse timing resolution down
jon> to
jon> 100 nS.  Since this device is totally asynchronous to the CPU, the CPU
jon> needs to have a way to count those pulses, so you need a quadrature
jon> encoder counter chip, too.  That chip can either count stepper pulses or

matt shaver, described this work to me when i talked with him.

jon> 
jon> use an actual shaft encoder on the motor.
jon> 
jon> Jon
jon> 

-- 
Terry L. Ridder
Blue Danube Software (Blaue Donau Software)
"We do not write software, we compose it."

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---