Fun with TK50's
Mr Ian Primus
ian_primus at yahoo.com
Fri Aug 10 18:38:22 CDT 2007
Well, in my adventures with this MicroVax II and it's
associated TK50, I have learned a few things about
A TK50 drive has phillips head screw-heads on both
reels (underneath, through hole in board for
supply/cartridge reel, and in the center of the take
up reel on the top). This allows you to manually
rewind a tape that's jammed in the drive.
When you rewind a tape that's been stuck in the drive
for who-knows-how-many years, it won't necessarily
load the next time. Some portions of the tape were
wrapped unevenly and dragging inside the cartridge
(you can feel it, pusing in on the reel from beneath
It's possible to manually wind the entire tape out of
the cartridge in order to fix this, using only a
phillips head screwdriver. And provided you cleaned
the drive, it'll even rewind when power it back up.
Said cartridge won't actually hold data again,
however. (Can anyone say shoeshine?)
Tape cartridge design hasn't changed much. DLT III
tapes look almost identical, and would fit if it
wasn't for a plastic tab on the left of the tape.
Tape cartridges are so identical, in fact, that you
can disassemble your dud TK50, and move the bottom
part of the shell over to a DLT III cartridge,
allowing you to insert it into a TK50 drive.
As clever as this seems, it doesn't work at all. Not
that I really expected it to, TK50's are 350 orsted,
DLT III's are like 1540 orsted. The media is very,
very different. I just wanted to see what would
In case you're curious, such a tape will thead up,
load, then give an error. The tape won't properly
rewind and unload either, you have to do it manually.
You't think that the designers would have thought of
this, and implemented some system of preventing you
from inserting a DLT III tape into a TK50 drive. Like
a plastic tab or something. Oh, wait...
A TK50 cartridge makes a rather thick, but
Just in case anyone else wanted to know :)
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