Program boundaries – HP 15c User Manual

Page 77

Advertising
background image

Section 6: Programming Basics

77


Keystrokes

Display

1 ´ m %

1.0000

R

1

and R

0

allocated for data

storage; R

2

to R

65

available for

programming and advanced
functions.

19 ´ m%

19.0000

Original allocation: R

19

(R

.9

) and

below for data storage; R

20

, to

R

65

for programming and

advanced functions.

*

lm%

19.0000

Displays the current highest data
register.

The m and W (memory status) functions are described in detail in
appendix C.

Keep in mind that an error message will result (given the above memory
configuration)
if

1. You try to address a register higher than R

19

(R

.9

), which initially is

the highest register allocated to data storage (

Error 3

).

2. You have 322 occupied program bytes and try to load more program

lines (

Error 4

).

3. You try to run an advanced function with insufficient available

memory (

Error 10

).

Program Boundaries

End. Not every program needs to end with a n or ¦ instruction. If
you are at the end of occupied program memory, there is an automatic
n instruction, so you do not need to enter one. This can save you one
line of memory. On the other hand, a program can ―end‖ by simply
transferring execution to another routine using t (section 7).

Labels. Labels in a program (or subroutine) are markers telling the
calculator where to begin execution. Following an ´ label or G label
instruction, the calculator will search downward in program memory for the

*

For memory allocation and indirect addressing, registers R

.0

through R

.9

are referred to as R

10

through R

19

.

Advertising