Re: Ciderpress Possible Problem Reading CP/M Disks

["Bill Buckels" <bbuckels@mts.net>]

"Steven Hirsch" <snhirsch@gmail.com> wrote in message 
yYGdnUMg-ezHhqrUnZ2dnUVZ_rrinZ2d@giganews.com">news:yYGdnUMg-ezHhqrUnZ2dnUVZ_rrinZ2d@giganews.com...
>Anyone know what "magic bytes" CiderPress is looking for?

I wish I did but what I have is a disk that worked and after several edits 
in both cpmtools and native CP/M in an emuilator it was no longer readable 
by ciderpress but ran fine in an (Apple II Oasis) emulator, and on a real 
Apple //e.

When I tried to duplicate the problem I couldn't.

I started with a plain old 56K CP/M 2.2 Softcard disk. Nothing special. 
ERAsed some files, APDOSed some files, cpmcp'd some files, cpmrm'd some 
files. fsck'd the thing etc. No problems reported.

I still have the disk that Ciderpress doesn't like of course, but that does 
little good if I don't know what it doesn't like about it. I will continue 
to try to duplicate the problem as I get time until I can nail-it down. I 
just was wondering what others had experienced.

Was the CP/M support in Ciderpress an afterthought that used "Magic Bytes" 
(I dunno)? Why does Ciderpress just open a CP/M disk in Read-Only? Is the 
code missing some information about the file system? I dunno. Is Michael 
Haardt's routine working properly for removing and adding files in cpmtools? 
Again, beyond me at this point. If I could duplicate the point that the 
problem occurs I could tell more and I save a copy of the last good disk 
before testing.

I'll keep trying then binary diff the good and bad disks. That should tell 
me more.

The process that I am following for my testing of cpmcp is to use APDOS to 
transfer a file from the Apple II Disk to both CP/M disks.

Then use my bhead.com to make one file on the first DISK, and cpmcp to copy 
the file to the second DISK. Presumably if the copy doesn't work on the 
second disk (i.e. it is unreadable in ciderpress) then I can diff the 2 
disks for clues. The files are identical so the difference in strategy for 
adding the files may be the culprit.

The second test for cpmrm is to simply use a process like the above to ERA 
the same file in CP/M on disk 1 and use cpmrm to remove the file from Disk 
2. This is tedious because between each operation I need to then attempt to 
view Disk 2 in ciderpress to see if it fails to be read.

Eventually I'll find it. I wish I had paid more attention though to the 
point where it broke.

If I suspect the problem is not Ciderpress I can certainly create a debug 
version of cpmtools and step-trace through it until I see if something goes 
wrong.

Bill