HP 15c - Manual (Page 77)

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
.