🚀 go-pugleaf

In article <1992Aug10.011313.25070@menudo.uh.edu> cosc16to@menudo.uh.edu (Andy Hakim) writes:
>lasner@watsun.cc.columbia.edu (Charles Lasner) writes:
>: 
>: Since data compression isn't a stagnant issue, Teledisk bucks that trend by
>: offering an arbitrary (albeit useful) compression method.  Further, since
>: compressed data can't be further compressed, this means that when you
>: attempt to archive these files with another utility such as LHARC or PKZIP,
>: there are some problems:
>
>WARNING:  I dont believe that the compression technique offered by 
>teledisk v2.12 is stable!  On several ocassions, when I have used 
>the compress option when creating IBM disks, I have received a 
>"CRC error" while restoring.  
>

Since we are giving serious attention to a program that is the lifeblood of
archiving data as proposed, I give the subject of bug reports a high priority.
Let's work to eradicate problems before we commit to it.

Please explain exactly what you were doing:  It sounds like the disk
was created incorrectly, not that Teledisk per se is having problems.  Do 
you have VERIFY ON in your system?  This could just be a hardware fault or
crummy media.  If the message goes away with VERIFY OFF but the media is
still unreadable due to CRC error after the fact, this may be more a problem
of your machine than Teledisk, or so I hope!  Can you repeat the problem
at will, or is it transient.  It would seem that you are saying that if you
run the program several times, then when a copy is made without a CRC complaint
the data is OK?  Or are there cases that *always* get an error and are 
esentially non-recoverable?  Does the compression setting matter relative to
the data being restored to original format?  BTW, Teledisk has no option to
not compress as you imply.  There are only two options, to compress or to
"advanced" compress.  The minimal compress is run-length compression, and
possibly zeroes repeat compression only; not sure which.  The advanced is
the full nine yards compression ala LHARC.

BTW, another potential gripe about LHARC could apply to Teledisk.  If you
choose to use advanced compression, and the data grows on account of
it instead of shrinking, you have to go back and use the run-length version
to get it back to a length closer to the original instead of longer.  Since
there is no way to create a standard length version without compression, you
wind up doing it both ways to find out, etc.

Let's attempt to clear up these matters soon; if Teledisk gets a "clean bill
of health" I'm all for using it in archiving stuff on RX50.

cjl