Civileme....thanks, that was interesting, if not just a little
bit over my head. I tried burning another cd before I swapped
out the reader in the problem machine and got an error about a
limit of 100 transsforms per track and that the cd I was copying
had exceeded that (Circadian Software's GPL cd of mdk 7.0). So
my copying was unsuccessful (adaptec software in windows).
Alan
Civileme wrote:
>
> Alan Shoemaker wrote:
>
> > Alan Shoemaker wrote:
> > [snip]
> > >
> > > Finally I attempted an Air (7.0) install on my wife's machine
> > > over her Venus (6.0) installation. It failed at the point of
> > > initializing the cdrom. I made a boot disc to use the text
> > > install and it failed too, at initializing the cdrom. I then
> > > installed Helios (6.1) on that machine (to see if it would have
> > > any problems) without a hitch.
> > >
> > [snip]
> >
> > This is an update on the above problem. I've successfully
> > installed Air (7.0) on the above machine by swapping out the
> > cdrom drive for another. After the drive change the
> > installation went flawlessly. I guess that the drive was not
> > reading the cd very well and at a certain point the read
> > problems would crash the install. I've seen this behavior
> > before, but still don't understand why it doesn't generate an
> > error message?
>
> Depends on the severity of the error. In algebraic coding theory we
> can use the (much more complex) polynomial multiplication/division
> schemes to recognize and correct m errors in a message of n bits
> (utilizing primitive monic polynomials in the Galois field of
> 2^(m+n) for example). What happens with exactly one too many
> errors? The error is recognized but not corrected (decoding
> failure) and with more than that the message is decoded into the
> WRONG one (decoding error).
>
> The scheme used on CDs (and most use CRC or checksum) break down
> when enough errors occur to introduce a correct checksum. This
> means that the error occurs and is not recognized. Presto, a jmp
> becomes an add and awayyyyy we go. In most cases, I have seen an
> error message, but I have had The same result and usually changing
> the CD drive (or just burning a copy from a drive that reads the CD
> correctly) cures the problem.
>
> The idea that CD drives are different enough to read badly kinda
> gives me a warm and fuzzy feeling inside. I know I should have
> gotten that flu shot.
>
> Civileme
>
> >
> >
> > Alan
>
> --
> experimentation involving more than 500 trials with an
> ordinary slice of bread and a tablespoon of peanut butter
> has determined that the probability a random toss will
> land sticky side down (SSD) is approximately .98
