18 Jan
2016
18 Jan
'16
9:46 a.m.
On 01/18/2016 10:56 AM, js at cimmeri.com wrote:
Interesting. I just happen to have a 3M Black Watch tape
right here next to me that I'm using to test a Mark 300
tape cleaning machine. The tape so far is fine, not
shedding anything front or back.
Sorry about previous reply, hit wrong button.
Well, I don't know if it was the Black Watch that was the
problem, or somebody else's version.
We started with spring-arm drives, which could not keep
constant tension on the tape. You'd hear this HORRIBLE
scrunch noise at various times when the tape was being
processed, which was the layers of tape sliding over each
other. Usually didn't cause problems, but on occasion it
could be so bad that the drive would lose tension and shut
down in the middle of the reel.
Vacuum column drives didn't seem to have much of this
problem. I think it was the jerk of tension when the drive
reversed to reread a bad block that started the slipping on
the spring arm drives.
Longevity of tapes was very spotty. Some expensive,
name-brand tapes just disintegrated after a few years.
Others have held up amazingly well. Last year I read in
some 1993 backups of my MicroVAX system with no trouble at
all. I did have to clean the tape head after every tape,
but that wasn't greatly different from when the tapes were new.
Jon