HP HP-25 - Page 97

When you hold the B3 key down in RUN mode, the program
step number and keycode for the previous step are displayed.
When you release , the X-register is again displayed. How-
ever if you switch back to PRGM mode, you will find that the
previous step is now displayed. And if you press[R/s]in RUN
mode after pressing EgJ, the calculator will begin execution
from the previous step in program memory. Now press (g in
RUN mode to review the program instructions of the above
program.
Press Display
BST 1 Holding E3fdown in RUN
mode displays the previous
instruction.
314.16 Releasing the B key displays
the original contents of the
X-register.
(53 02 15 73 Again holding B3l down dis-
plays the previous step in
program memory.
314.16 And releasing displays the
original contents of the X-
register again.
o w
o
If you now switch to PRGM mode the second step will be
displayed:
02 15 73
Cued Stops. If you have a program that is halted several times
during execution for data entries, you may want to ‘‘identify”’
each stop by recording a familiar number into the program just
before each [r/s] instruction. Then when the calculator stops
execution because of the[R/s] instruction in the program, you
can look at the displayed X-register to see the ‘‘identification
number’’ for the required input. For example if your program
contains eight stops for data inputs, it may be helpful to have the
numbers 1 through 8 appear so you know which input is re-
quired each time. These identification numbers are helpful in
editing a program.