GMC SIERRA 1994 Manual page 157

PROG
To go from one side of the tape to the other, press the PROG button.
Observe the lighted arrows to determine which side of the tape is being
played.
If a tape is inserted with side "1" (or
"A")
up, then the up arrow means that
that side is being played. Likewise, a down arrow would indicate that side
"2" (or "B") had been selected. The player will automatically switch to the
other side of the tape when the first side ends.
REV
To rapidly rewind the tape, press the REV button. The tape will rapidly
rewind until you press either the PROG or E JCT button. If the beginning
of the tape is reached while in the REV mode, play will resume on the same
side of the tape.
FWD
To rapidly advance the tape, press the FWD button. The tape will rapidly
advance until you press either the PROG or E JCT button. If the end of the
tape is reached while in the FWD mode, the tape will change direction, and
play will resume on the opposite side of the tape.
EJCT
Press the EJCT button to eject the cassette tape from the player (the radio
will then play).
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