SAVING PROGRAMS SECTION 3
Page 3-1 RPC-320
Figure 3-1 W3 autorun jumper
INTRODUCTION
Program s are stored in an EPROM in socket U6. You
can store one or more programs, 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 store 800 lines of code. Your application could
be significantly more or less, depending upon the
number of comm ands/line, comments, and print
statements.
Despite the fact you may have a 128K or 512K RAM
installed, the maximum program size RPBASIC-52 can
run at one time is about 60K (including room for some
variable storage). The table below shows the maximum
capacity, maximum number of program lines, program
size at one time, and number of programs 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 cleared (set to 0).
To keep variables, you must save them before calling the
new progr am. When the new program is running, these
variables are restored. Use PEEK and POKE to read
and save numbers and strings. See Chapter 5, STORING
VARIABLES IN RAM for more information.
Binary data is saved and read from the EPROM using
BSAVE and BLOAD commands. The EP ROM has a
limited number of write cycles (about 1000), so writing
information should be kept to a minimum.
A flash EPROM is non-volatile (retaining data even
when power is disconnected), having an unlimited
number of read cycles and a limited number of write
cycles (about 1,000). A program is not run from
EPROM . It is transferred to RAM and run from there.
Programs in RAM can be modified. 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.
This chapter discusses saving programs to EPROM (U6)
and program autoexecution.
SAVING A PROGRAM
For this example, assume you wanted to save the
following program:
20 FOR N= 0 TO 2
30 PRINT "Hello ",
40 NEXT
50 PRINT
If this progr am is not already in, type it in now (or , if
you prefer, use your own program).
Type in the following command:
SAVE
RPBASIC-52 responds with:
Saving 35 bytes
Verifying --- OK
