Saving Programs, Saving a Program | Remote Technologies RPC-320

SAVING PROGRAMS

INTRODUCTION

Program s are stored in an EPRO M in socket U6. You can store one or mor e program s, depending upon EPROM size. A BASIC program can call another when a 512K byte EPROM is used.

Maximum program size that can be run at any one time is about 62K, not including space for variables. 32K bytes is the maximum program size when a 29C256 IC type is used to save a program .

A conservative rule to determine program memory requirements is one line requires 40 bytes. 32K bytes would stor e 800 lines of co de. Your application cou ld be significantly more or less, depending upon the number of comm ands/line, com ments, and pr int statements.

Despite the fact you may have a 128K or 512K RAM installed, the maximum progr am size RPBASIC-52 can run at one time is about 60K (including room for some variable storage). T he table below shows the maximum capacity, maximum number of program lines, program size at one time, and number of program s for an EPROM type.

EPROM	Max	Prog	Max	No.
type	Cap.	lines	Bytes	Progs
29C256	30K	400	32K	1
29C040	509K	12400	62K	8

One program can call another using the EXECUTE n command. n is from 0 to 7, depending upon the EPROM type.

NOTE: When a program calls another, the old program is completely replaced. All variables and arrays are clear ed (set to 0).

To keep variables, you m ust save them before calling the new progr am. When the new program is running, these variables are restored. Use PEEK and P OKE to read and save numbers and strings. See Chapter 5, STORING VARIABLES IN RAM for more inform ation.

Binary data is saved and read from the EPR OM using BSAVE a nd BLOA D com mands. The EP ROM has a limited number of write cycles (about 1000), so wr iting information should be kept to a minimum .

SECTION 3

Aflash EPROM is non-volatile (retaining data even when power is disconnected), having an unlimited numbe r of re ad cycles an d a limited nu mber of write cycles (about 1,000). A program is not run fr om EPROM . It is transferred to RAM and run from there. Prog ram s in RAM can be m odified. They ar e saved to EPROM for execution later .

The RPC -320 can autorun on power up or r eset by removing jumper (W9). W hen autorun is on, the program in EPROM segment 0 is loaded into RAM and begins to execute immediately.

Figure 3-1

W3 autorun jumper

This chapter discusses saving programs to EPR OM (U 6) and program autoexecution.

SAVING A PROGRAM

For this example, assume you wanted to save the following program:

20 FOR N= 0 TO 2

30PRINT "Hello ",

40NEXT

50PRINT

If this progr am is not alr eady in, type it in now (or , if you prefer, use your own progr am).

Type in the following command:

SAVE

RPBASIC-52 r esponds with:

Saving 35 bytes

Verifying --- OK

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