Remote-processing BASIC 52 Manual do Utilizador descarregar pdf (Página 70)

RPBASIC-52 PROGRAMMING GUIDE

2-51

LD@

Syntax: LD@ expr

Where: expr = valid integer address of 00H through 0FFFFH (65535)

Function: Retrieves a floating-point number previously saved with ST@

Mode: Command, run

Use: LD@3000

Cards: All

DESCRIPTION

LD@ is used in conjunction with PUSH, POP, and ST@ . Use these commands to save and retrieve floating

point numbers to program RAM.

NOTE: LD@ and ST@ cannot use extended RA M. Only se gment 0 R AM (used for running B asic

programs) is used. Use PEEKF and POKEF commands to access this memory.

WARNING: When 128 K and 512K RAM are installed, all of m emo ry is cleared on pow er up and 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 RAM systems have address 7E00H set as M TOP. T his location up to 7FFFH m ay be used to store

variables.

expr is the ad dress in RAM of w here a number is sto red.

Each floating-poin t number requires six bytes of memo ry. expr in the ST@ and LD@ instructions specify the

high address. A number is stored at locations expr through expr-6.

ST@, PUSH, POP, PEEKF POKEF

ERROR

BAD ARGUM 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

1 2 ... 65 66 67 68 69 70 71 72 73 74 75 ... 162 163

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Remote-processing BASIC 52 Manual do Utilizador Página 70