Tandy 1000 Basic Reference Manual page 267

Chapter 10
I
BASIC Keywords
PLAY/Trap Statement
PLAY action
Turns on, turns off, or temporarily halts background music event
trapping.
Action may be any of the following:
ON enables play event trapping.
OFF
disables play event trapping.
STOP
Use the PLAY/Trap statement in a background music trap rou-
tine with the
ON
PLAY GOSUB statement to detect when the
number of notes in the background music queue goes from num-
ber to number minus 1.
The PLAY
ON
statement turns on the trap. BASIC checks the
number of notes in the background music queue after each pro-
gram line. If the number is equal to that in the
ON
PLAYO
GO-
SUB statement, BASIC transfers program control to the line
number specified.
The PLAY STOP statement temporarily halts background music
trapping. If the number of notes equals the specified number,
BASIC does not transfer program control
to
the
ON
PLAYO GO-
SUB statement until you turn on trapping again by executing a
PLAY ON statement. BASIC remembers that the number of
notes was equal and branches to the subroutine immediately
after trapping is turned on again.
The PLAY
OFF
statement turns off background music trapping.
BASIC does not remember if the number of notes in the queue is
equal to the number specified when trapping is turned on again.
See
ON
PLAYO GOSUB for more information about background
music trapping.
temporarily suspends play event trapping.
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