Remote Processing BASIC 52 - Manual (Page 126)

RPBASIC-52 PROGRAMMING GUIDE
2-107
STRING
Syntax: S T R I N G total bytes,string leng th
Where: total bytes = total num ber of bytes in m emory to allo cate
string leng th = maximum number of bytes in a string
Function: Allocate memory for strings
Mode: Comm and, run
Use: STRING 56,10 : REM Allocate memory for 5 10-byte strings
Cards: All
D E S C R IP T I ON
Prior to using strings, you m ust use STR ING to alloc ate mem ory for them. Th e STR ING argu ment valu es are
computed by this equation:
total bytes = ((string leng th + 1) * number_of_strings) +1
The only way to recover string memory is with a "STRING 0,0" instruction. String memory is reclaimed and
t h en r ea l lo c a te d e ac h ti m e y ou u se t he S T R IN G o p e ra t or . S t ri n gs a re t er m i na t ed w i th a c ar r ia g e re t ur n (0 D H
or 13) which is the additional byte ad ded to your bytes per string expr.
WARNING:
STRIN G causes RPB ASIC-5 2 to execute the equivalent of a C LEA R instruction sinc e string and num eric
variables occupy the same m emory space. In other words, the STR ING instruction clears all variables,
interrupts and stacks. Allocate string memory early in your program and don't reallocate it unless you can
accept the loss of all variables.
RELATED
ASC, CHR, STR
ERRORS
M E M O R Y A L L O C A T I O N Memory not allocated for strings
C - S T A C K STRING used in a subroutine, clearing the stack.
EXAMPLES
10 STRING 1000,40
20 $(0) = "Up to 40 characters in this string"
.
.
100 $(2) = COM$(1)