Antitrack_at_networld.at
Date: 2008-01-28 12:03:50
Quoting ruud.baltissen@abp.nl:
> An update on my project so far:
> I have multiple imaging working now for 99%. This 1% is one of the two
> weird problems I have encountered so far. The first one costed me at
> least three days. I had things reasonably going fine and then....
> nothing on my screen any more. If I wanted to list the image directory I
> only got the number 8224 on the screen. At the end I found out that
> using the addresses $023C and $023D for some temporary variables caused
> the trouble. I didn't find any references to these addresses and yet
> they are used.
YES, they are used, I have the best reference ever, the book
"Die Floppy 1541", Author: Karsten Schramm, 64'er Publishing,
ISBN 3-89090-098-4, in german. Hereby losely translated:
$022b-$023d : "channel table, contains the status for each channel:
$ff : not used
$81 : channel opened for writing
$41 : channel opened for read+write
$01 : channel opened for reading
$023e-0243 : current data byte for each channel
Perhaps the best idea is to use $0000 - $0005 for zeropage vectors
(which can be weird, dont interfere with the jobcodes!),
$001b is officialy not used!
$0035, $0037, $003b/$003c not used!
$0046 not used
$00b5-$00c0 : "lo and highbyte of record number for each buffer"
so if you don't work with records...you can maybe use it...
You could maybe have used the input buffer $0200-$0229...
Other than that, you're well adviced to use $0300-$07ff for your own stuff...
Hope that helps. I can scan in the pages 165-173 from said book if needed,
but it's in german!
Yours
ATT
--------------------------------------
Ein Service von http://www.networld.at
Message was sent through the cbm-hackers mailing list
Archive generated by hypermail pre-2.1.8.