Appending to cart tapes

[Kalman Reti <Reti@STONY-BROOK.SCRC.SYMBOLICS.COM>]

    Date: Mon, 21 Aug 89 14:38 EDT
    From: David A. Moon <Moon@STONY-BROOK.SCRC.Symbolics.COM>

    I have a vague memory that way back years ago, not long after cart tapes were
    first put on 3600s, we tried using the documented commands to the drive for
    appending to cart tapes.  The result, on at least some drives, was that the
    drive went amuck and physically destroyed the cartridge (it filled up the
    inside of the cartridge with crumpled up tape).  I'm sure this happened on
    more than one drive, it wasn't just one broken drive.  I haven't been able
    to remember any more details, but I do remember a lot of laughter about this
    low-quality aspect of the cartridge tape drives.  
I do remember a lot of comments about low quality also, but I'd never before heard
of the physical crumpling; I do remember one incident where the tape was pulled
off its hubs, but I think that was a burnt out sensor light.
						      At this point it would
    have been logical to decide not to try to implement appending, because we'd
    much rather have customers complaining that they couldn't append than have
    them complaining that we had destroyed their valuable backup tapes.

    Kalman, do you remember anything about this?  It might have been before your
    time, but I don't think so.
It wasn't before my time, but I never heard anything like this.  The people I
remember working on it were Jim Culp, Bernie Greenberg and somebody else (Cassels?,
DCP?);  I remember talking to Bernie and having him assert with some authority
that they didn't do appending, but I don't think he ever told me on what basis
he made the assertion.  However, I wasn't paying a lot of attention to it at the
time, and certainly wasn't in the thick of things.