Re: A Problem

[Chris Albertson <chrisalbertson90278@yahoo.com>]

Many older computers had a BIOS seting called something like
I/O wait states.  It would "wait state" the CPU a specified
number of clock cycles after every I/O request to the ISA
bus.  It was pretty common that you needed it.  I think you
need to find that setting and make it bigger, or simply
under clock the whole system.  Can your 1Ghz system be set
to run at 500Mhz?  Are maybe there is a "bus ratio" seting
that runs the ISA bus at a specified faction of the system.
Or there could just be a busspeed setting.

I think what's happening is that the CPU is expecting the
data to be present before it is and you are seeing dropped bytes
dropped single bytes would look like a byte swap.

I wrote a Linux device driver for the Mk IV card that tuned out
to be as fast as the hardware allowed.  It just issued one instruction
to read ut a block of data.   This may be what you are doing.
maybe it's wrong to do that on a fast PC?  Try reading each byte
out then add a delay loop between each read.  Likely the shuttle
is running the ISA bus to fast for your 7400LS based borads.

I have a working P200 (or maybe it's a P100?) that has an ISA
bus that I'd be happy to swap for a 1Ghz shuttle.  I'm sure you
will find a long line of people willing to make the same trade.

Those shuttles would make pretty decent Linux servers. With the
amount of computers you have you could use a centeralized file
server.


--- Thomas Droege <tdroege2@earthlink.net> wrote:
> Anticipating that ISA computers would be hard to get in the future, I
> laid
> in a supply.  3 nice 1 GHz Shuttle computers.  Just right for running
> cameras, I thought.
> 
> I have discovered that these computers will not read my memory board.
>  I
> don't know what the problem is, but it looks like it either reads the
> bytes
> one byte off or possibly reversed from what other PCs do.
> 
> Is there anything to adjust in the BIOS that might change how bytes
> are
> read from the ISA bus?  Is it possible that the Shuttle was just
> never
> tested reading data from the ISA bus?  It might also be a timing
> problem. 
> Are there any BIOS adjustments that change the speed of I/O
> read/writes?  
> 
> Sigh!
> 
> I hate the throw three perfectly good computers into the trash.  But
> I
> really don't have much use for these for anything but reading
> cameras.
> 
> Tom Droege
> 
> 
> Tom  Droege Jennifer Malpass
> tdroege2@earthlink.net
> 
> 
> 
> 


=====
Chris Albertson
  Home:   310-376-1029  chrisalbertson90278@yahoo.com
  Cell:   310-990-7550
  Office: 310-336-5189  Christopher.J.Albertson@aero.org
  KG6OMK

__________________________________
Do you Yahoo!?
Yahoo! Mail SpamGuard - Read only the mail you want.
http://antispam.yahoo.com/tools