-=> Mocking Jerry Coffin to Kurt Wismer <=-
   
 JC> Well, I did some more looking at it, and actually did some testing on
 JC> the result this time.
and you solved the problem too, thanks for the follow up... i did
aswell after i started playing with a debugger and stepping through
the program...
 JC> mov dx, 0ffffh
 JC> arge:
 JC> inc dx
 JC> xor ax, ax
 
and the problem was that xor ax, ax... i put it before arge: and as a
result it wasn't 0 after the first pass through the loop... dos wound up
being told to check drive number 2 instead of 0 (and there is no drive
2)...
 JC> It seems to produce a reasonable backup of a
 JC> full disk, though I haven't done extensive testing.
well, i've done more testing on it (and my version after i fixed the
original problem) and i found a new glitch, or at least it's a
behaviour i don't understand... the 4626 byte image file is invalid, it
should (though i didn't realize this before) be 16962 bytes... if the
floppy drive is not read in any way before the program is executed the
4626 byte image is produced but running a hex editor like norton
diskedit or even just performing dir a: before running the disk backup
program will result in the 16962 byte file being produced (with both our
versions of the program)...
 JC> This should assemble to 89 bytes.
it did when i commented out the ".stack"....
 JC> be shaved off as well.  Then again, if you really want to use this,
 JC> you'll probably want to add some feedback to the user during operation,
 JC> which is likely to occupy almost as much space as the real guts of the
 JC> program...
how true... a restoration routine would probably be good too...
... Virus Alert/Tagline Virus, avoid "Virus Alert" infected taglines...**
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