19 Feb
1999
19 Feb
'99
12:06 a.m.
Don Maslin wrote:
[snip...]
Don,
Looking at a DC-100 cartridge, both sides of the tape look about equally
glossy. I assumed that the oxide side was on the "outside" becasue that
is the surface where the R/W head contacts the tape.
Even if my assumption is incorrect, it may just be the continued
pressure of the drive band against the layers of tape that causes the
oxide to stick to adjacent layers and peel off. What I *do* know is that
the oxide does peel off in areas corresponding to the location of the
drive band.
Stan
One caveat on buying used DC-100 tapes: when the tapes are stored for a
long time and not regularly wound and rewound, the "rubber band" inside
the cartridge (that actually moves the tape) can damage the oxide and
cause it to lift from the tape backing. Usually the oxide comes off the
BOT area of the cartridge, and not only does this remove the directory
area, but the now transparent area of the tape confuses the EOT sensors
and makes the tape totally unusable. Probably 90% or more of the HP-85
and HP 9825 tapes I've found at swap meets are damaged in this manner.
Even tapes that have never been used and are still shrink wrapped may be
damaged in this way if they're old enough.
Stan, how can that happen? Every cartridge tape that I have run across -
from DC-100 to DC-2120 and beyond - is spooled such that the oxide face is
towards the hub of the spool and NEVER comes in contact with the drive
band. I have had tape layers stick together from old age and lack of use,
and certainly broken drive bands, but...
- don