HP HP-65 - Programming; Looking at a Program

Section 4
Programming
In the Introduction you learned to run a prerecorded program
and to create a simple program. You have since explored the
preprogrammed abilities of the calculator. This section provides
the information for creating more ambitious programs, com-
parable in scope to the recorded programs in the Standard Pac
and other pacs. You are encouraged to create and use your own
programs even though you otherwise take full advantage of your
calculator’s power by merely using prerecorded programs. We
think you will find it as exciting as it has been for us.
To create a program, you need to:
. Define the problem.
. Work out the keystroke sequence that solves the problem.
. Add control operations for automatic execution.
. Key the keystroke sequence, including control operations,
into program memory.
. Edit, verify, and record the sequence for later use.
. Run the sequence, automatically, with your data.
AW
-
AN
W
To key a program into the machine, press the successive keys
with the switch in W/PRGM position. Then, by passing an un-
protected magnetic card through the right lower slot of the cal-
culator, you can save the program (contents of the 100-step pro-
gram memory) for future use.
The subject is discussed under four major headings: * Look-
ing at a Program. = The Control Operations needed in pro-
grams to start, to repeat, and to stop. ® The Editing Operations
that allow you to correct and change programs in memory. =
Test Operations that allow your program to make decisions.
Looking at a Program
Quite obviously, it is not possible to see the entire program at
once; you see one step at a time as determined by the program
pointer (defined in Figure 4-1). Recall that program memory
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