HP 113394 User Guide - Page 112

112 Section 8: Programming Basics

File name: hp 12c pt_user's guide_English_HDPMF123E27

Page: 112 of 275

Printed Date: 2005/8/1

Dimension: 14.8 cm x 21 cm

The

000 Instruction and Program Line 000

Whenever you run the program now stored in program memory, the calculator

executes the instruction in line 008 after executing the seven instructions you keyed

in. This

i

000 instruction — as its name implies — tells the calculator to “go to”

program line 000 and execute the instruction in that line. Although line 000 does

not contain a regular instruction, it does contain a “hidden” instruction that tells the

calculator to halt program execution. Thus, after each time the program is run, the

calculator automatically goes to program line 000 and halts, ready for you to key

in new data and run the program again. (The calculator is also automatically set to

program line 000 when you press

fs

to set the calculator from Program mode

to Run mode or when

f

CLEAR

Î

is pressed in

run

mode.)

The

i

000 instruction was already stored in line 008 — in fact, in

all

program

lines —

before

you keyed in the program. If no instructions have been keyed into

program memory, if Continuous Memory is reset, or if

f

CLEAR

Î

is pressed (in

Program mode), the instruction

i

000 is automatically stored in program lines

001 through 008. As you key each instruction into program memory, it replaces

the

i

000 instruction in that program line.

If your program should consist of exactly eight instructions, there would be no

i

000 instructions remaining at the end of program memory. Nevertheless, after

such a program is executed the calculator automatically returns to program line

000 and halts, just as if there were a

i

000 instruction following the program.

If you key in more than eight instructions, program memory automatically expands

to accommodate the additional instructions.

Expanding Program Memory

If no instructions have been keyed into program memory, if Continuous Memory

has been reset, or if

f

CLEAR

Î

has been pressed (in Program mode), program

memory consists of 8 program lines, and there are 20 storage registers available

for storage of data.

HP 113394 User Guide - Page 112

Instruction and Program Line 000, Expanding Program Memory

Page 112 highlights