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Re: A Problem
Well, I played with the BIOS. The most recent thing that I did was to set
UART2 from normal to the other possible setting.
Then it worked. Then I tried setting back to the old value. It worked.
Now I cannot find a mode where it does not work.
Last I set it to all the default values and it worked.
Sigh!
There seem to be two possibilities:
1) It is a warm up problem. The card works only after it has run a while
and has warmed up. This is definitely possible.
2) It is a BIOS initilization problem. The BIOS starts out in some funny
state. Changing anything resets it so that the ISA bus works.
Sigh! I was tired of trying to fix it. Now I am tired of trying to break
it so that I understand what is wrong. Well, I have 2 more computers to
try to see if the error comes back. If it does, I can sort out the BIOS
problem from a warm up problem.
At least at the moment TOM1 is running and I am on the way to having a set
of working systems.
Tom Droege
> [Original Message]
> From: Chris Albertson <chrisalbertson90278@yahoo.com>
> To: <tdroege2@earthlink.net>; tass <tass@listserv.wwa.com>
> Date: 2/19/2004 6:24:50 PM
> Subject: Re: A Problem
>
>
> 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
>
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