Homebrew STG card - CRAZY-4

["Arne Chr. Jorgensen" <instel-at-online.no>]

Hi,

I do have a big trouble to stop this :)  

Well,  if this is of any interest and we join in on it,  we could make it work.

I think I forgot to mention this:

The idea is to download everything from the linux box.  And I thought of having
these boxes close together.

But - you could use ethernet cards.  Say you used shielded twisted pair, and
wired them together without any hub. ( excange send/receive wires)  You could
get 100Mb/s - which should do.  Even 10Mb/s should be good enough.

You could also get an eprom install on this ethernet card, so it would download
all from the other one.  I would have two cards in the Linux box.  One
dedicated just to this other subsystem.  I just don't know how it would work to
have this one run in the RT space,  but Will& Fred would probably know.

This could be the simplest and cheapest way to do it.   


A few other notes - some may think that this must be strange - say use a XT
computer, while we now use several hundred MHz cpus.  But in fact, this could
outperform our other boxes !!  

The ISA bus only run at 8MHz - and RTLinux uses it just in a small frame of
time.  These other boxes could use it at a much longer time frame, and they
have no trouble of keeping the ISA speed.  ( Well, XT would )  but still, -
this is a degrade of performance.

About stacking up as many stepper axis you like:   The thing is - we can use
almost all the IO space we like to.  There is not other cards we need to be
concerned with.  

There is some limitations on interrupts available, but having a cpu to hour
disposal,  then it could service these, do some polling and remap it into a
message that goes back to the Linux box.  We could have many cards sharing the
same interrupt, if needed.       


Well,  I don't know what you would think of this - and I will look forward to
hear what you have to say.  

//ARNE