Tandy 1000 Basic Reference Manual page 119

Chapter 10 I BASIC Ke-ywords
CLEAR
Statement
CLEAR [,memory location.] [,stack space][,uideo
memory1
Frees memory for data without erasing the program currently in
memory. CLEAR erases all arrays, sets numeric variables to
zero and string variables to null, and erases any information set
using a DEF s t a t e m e n t , such a s DEF SEG and DEF FN.
CLEAR also turns off the SOUND, PEN, and STRIG functions
and resets the music background.
Since CLEAR initializes all variables, place it near the begin-
ning of your program, before any variables have been defined
and before any DEF statements.
Memory
location must be an integer. It specifies the highest
memory location available for BASIC. The default is the current
top of memory as specified with the
/M:
switch when BASIC was
loaded. This option is useful if you will be loading an assembly-
language subroutine, because it prevents BASIC from using that
memory area.
Stack space also must be an integer. This sets aside memory for
temporarily storing internal data and addresses during subrou-
tine calls and during FOR/NEXT loops. If you omit stack space,
BASIC sets aside 768 bytes or one-eighth of the memory avail-
able, whichever is smaller. BASIC displays an "Out of memory"
error if stack space for program execution is insufficient.
Video memory is an integer that specifies the amount of memory
to be set aside as video memory. For graphics modes, if the v d e o
memory
you specify is not a multiple of 16K bytes (16384 bytes),
BASIC rounds it down to the nearest multiple of 16K. If you
omit video
memory,
BASIC sets aside 16K. The video memory
page size for each screen mode
is
described
in
Chapter 8, "Dis-
playing Color and Graphics."
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