HP HP-67 User Manual

138 Simple Programming
Executing Instructions
When the calculator found the [ I3 instruction in step 001, it
ceased searching and began executing instructions. The calculator
executes instructions in exactly the order you keyed them in, perform-
ing the ) operation in step 002 first, then @ as in step 003,
etc., until it executes an [ instruction or a (runistop)
instruction. Since an [jJ instruction is executed in step 005, the
calculator stops there and displays the contents of the X-register. (To
see the next step number of program memory after the one at which the
calculator has stopped, you can briefly switch the W/PRGM-RUN
switch werewm [[[[IllruN to W/PRGM.)
If you key in a new value for the radius of a circle in RUN mode and
press £, the HP-67 repeats this procedure. It searches sequentially
downward through program memory until it encounters a a
instruction, then sequentially executes the instructions contained in
the next steps of program memory until it executes an () or a(R/S)
instruction.
You can see that it is possible to have many different programs or parts
of a program loaded in the HP-67 at any time. You can run any one of
these programs by pressing the letter key ({8 through &, (7 (&)
through {2 (€)) that corresponds with its label.
It is also possible to have several different programs or routines
defined by the same label. For example, suppose you had three
programs in your HP-67 that were defined by [2. When you
pressed {2, the calculator would search sequentially through program
memory from wherever it was located until it encountered the first
instruction. The HP-67 would then execute instructions until it
executed a ora instruction and stopped. When you pressed
again, the calculator would resume searching sequentially from the
or (R/S) through program memory until it encountered the second
a instruction, whereupon it would execute that {3 and
all subsequent instructions until it executed an [ or a [R/S
instruction and stopped. When you pressed a third time, the HP-67
would search downward to the third [ instruction and execute
that program.

HP HP-67 Specifications

General

Introduced	1976
Programming Steps	224
Memory Registers	26
Type	Programmable
Manufacturer	Hewlett-Packard (HP)
Display	LED (red)
Programming	Keystroke
Power	Rechargeable battery pack
Logic	RPN (Reverse Polish Notation)
Battery	Rechargeable battery pack