[Coco] Nitros9 & Mess
robert.gault at worldnet.att.net
Mon Feb 2 21:13:04 EST 2004
Nathan Woods wrote:
> Then again, it is always possible that I was chasing phantoms. I seem
> to have lost my notes from last September; Robert Gault, do you remember
Here are some details I observed with the directory corruption problem.
1) The problem varies with the version of OS-9 running but only with
emulation. I have only heard of this reported for MESS but it is
possible that other emulators have problems. The most recent versions
from Boisy have the most problems.
2) The corruption occurs with programs that edit files by opening a temp
file, deleting the original, and renaming the temp to the original.
Using the exact same .dsk image and Build or copy, a new file can be
created in a directory without corruption.
3) The directory corruption is as follows: The first sector of the
directory listing is copied over the second sector of the listing
resulting in duplicate . and .. entries (along with other files.) It is
the circular nature of the duplicate . .. entries that drives OS-9 crazy.
4) The problem may require that the first sector be filled. The problem
does not occur when editing a directory which has a single file.
As for the rest of the MESS debugger results, they seem to indicate that
the wrong block of RAM is being processed during the editing of the
directory structure. I can't quite remember whether the corruption
occurs before and editor like Scred exits or while the edit is in
progress. I think it is necessary to exit the program but that should be
I have thought that some obscure timing in emulation is at the root of
the problem but that is a guess.
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