Re: The Infamous Bad Data Problem

[Tom Droege <tdroege@veriomail.com>]

Chris and all,

I think I have a fool proof reset function built into the card.  This is 
why it has taken me so long to figure out this problem.

I think that Windows saves a byte somewhere.  Or possibly you are 
correct.  We use the space normally used by the game board?  We are using 
300H-303H as I recall.  We need 4 spaces anywhere from 200H to 
3FFH.  Anyone know what space would be safe?

Hmmmm!  Were I to switch to dos, how do I do it and what dos?  I think with 
Windows 98 you have windows whether you like it or not???  Also is there a 
dos that knows about large disk space?  It is now an operational 
convenience to have Windows available as the tools I use to look at data 
run under windows.

But I have sworn a sacred oath to learn something else now that Bill has 
escaped justice.

Tom Droege

At 09:14 PM 11/5/01 -0800, you wrote:

>Pure guess but I notice you picked an I/O space location
>for your register that is commonly used on network cards.
>I forgot the address (hex three hundred and something?)
>
>It's not random.
>Windows will poke around and try to find hardware by stuffing
>bytes into registers and reading them back out.  This could
>be the cause and it could also be why I don't see it on
>my card.   But I only used either Linux or just plain DOS,
>never Windows.  What you need is a fool proof reset function
>built into the card.  Either that or give up on using
>Windows :)
>
>Tom Droege wrote:
> >
> > As you all know, I have been plagued with a "bad data" problem.  It is most
> > likely caused by the data from the memory card being one byte off.  That is
> > what it looks like.
> >
> > Whenever it happens I take care to note what might have happened.  This
> > evening while testing TOM2, the bad data appeared suddenly.  It happened
> > just after I interrupted the program while it was in the middle of running
> > Rob's Download program.  After that, it read consistently bad data.
> >
> > I then shut down windows properly.  It shut down as if it was doing it
> > properly.  I turned off power, and when I turned it back on, it said that I
> > had not turned off the computer properly and did the memory scan
> > thing.  Now it read out the memory card properly.
> >
> > OK, it looks to me like Windows is stashing an odd byte
> > somewhere.  Possibly it is a random thing on turn on and it thinks that
> > there is an odd byte to read and does so.  The result is that sometimes
> > when I turn on the system reads out the bytes in correct sequence and
> > sometimes it is one byte off.
> >
> > OK, I accuse my hardware first.  But I have tried everything.  It is
> > beginning to really look like there is something in Windows that gets one
> > byte off on the I/O port, and then often remembers that on turn
> > on.  Barf!  This may be hard to believe.
> >
> > Now that several of you are trying to run Mark IVs and with different
> > operating systems, it will be interesting if you see this problem.  The
> > symptom is an image with -32k to +32k range and a sigma of large.  The data
> > looks like big time noise.  It suddenly comes and is hard to get rid
> > of.  Usually a few restarts of Windows will do it.  Sometimes it takes all
> > night.
> >
> > Tom Droege
>
>--
>
>--
>    Chris Albertson
>    Redondo Beach, California
>    home:   310-376-1029   chrisalbertson90278@yahoo.com
>    cell:   310-990-7550
>    office: 310-336-5189   Christopher.J.Albertson@aero.org