Pioneer X-NM1 Operating Instructions Manual page 36

The tape of a cassette is quite easily damaged and
loose tape can jam in the tape deck mechanism. If the
tape has become unwound, use a pen or pencil to
wind it back on to the spool.
When not using cassettes, always store in the case.
Store cassettes away from magnetic fields, excessive
heat, humidity, dust or oil.
Before recording on a tape, wind the tape on past the
leader tape (about the first 3 or 4 seconds of each
side).
Since tapes longer than 90 minutes are so thin, they
are more susceptible to jamming in the tape deck
mechanism and other trouble such as irregular
winding. Avoid using cassette tapes longer than 90
minutes.
You can protect an important recording against
accidental erasure by breaking the erase-protect tab(s)
with a small screwdriver.
If you want to re-record on an erase-protected cassette,
cover the space left by the broken tab with self-adhesive
tape.
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