Remote Processing BASIC 52 - Manual (Page 70)

RPBASIC-52 PROGRAMMING GUIDE
2-51
LD@
Syntax: L D @ expr
Where: expr = valid integer address of 00H through 0FFFFH (65535)
Function: Retrieves a floating-point number previously saved with ST@
Mode: Comm and, run
Use: LD@ 3000
Cards: All
D E S C R IP T I ON
LD@ is used in conjunction with PUSH, POP, and ST@ . Use these commands to save and retrieve floating
p o in t n u mb e rs to p ro g ra m R A M .
NOTE: LD@ and ST@ cannot use ex tended RA M. Only se gment 0 R AM (u sed for running B asic
programs) is used. Use PEEKF and POKEF commands to access this memory.
WARNING: Wh en 128 K and 512K RA M are installe d, all of m emo ry is cle ared o n pow er up a nd rese t.
Do not use LD@ or ST @ to save floating point numbers in segment 0. Use POKE and
PEEK type comm ands instead.
32K R AM sy stems hav e address 7E 00H set as M TOP. T his location up to 7F FFH m ay be used to sto re
variables.
expr is the ad dress in RA M of w here a num ber is sto red.
Each floatin g-poin t num ber req uires si x byte s of m emo ry. expr in the ST@ and LD@ instructions specify the
high address. A number is stored at locations expr through expr-6.
RELATED
ST@, PUSH, POP, PEEKF POKEF
E R R O R
BAD A RGUM ENT when expr > 65535
EXAMPLE
100 A=AIN(0)*.234
110 PUSH A
120 ST@7F00H
.
.
300 LD@7F00H
310 POP B
320 PRINT "Analog value retrieved=",B
>run
Analog value retrieved=",B