HP HP-67 User Manual

Section 13
Flags
Besides the conditionals (K=Y), (>0), etc.) and the tests for zero
(=21, 653, (M), Bszm), you can also use flags for tests in your
programs. A flag actually is a memory device that can be either SET
(true) or CLEAR (false). A running program can then zest the flag
later in the program and make a decision, depending upon whether
the flag was set or clear.
There are four flags, FO, F1, F2, and F3, available for use in your
HP-67. To set a flag true, use the instruction (SF) (set flag) followed
by the digit key (0], (1], (2], (3)) of the desired flag. The instruction
CF) (clear flag) is used to clear flags.
When using flags, decisions are made using the instruction (is
flag true?) followed by the digit key ((0], (1), (2), (3)) specifying the
flag to be tested. When a flag is tested by a ([} (n] instruction,
the calculator executes the next step if the flag is set (this is the ‘DO
if TRUE”’ rule again). If the flag is clear, the next step of program
memory is skipped before execution resumes.
Is flag F1 true?
YES NO
m E] =~
\
If YES, , I NO, skip
continue execution ¥ one step before
with next step. resuming execution.
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HP HP-67 Specifications

General

Brand	HP
Model	HP-67
Category	Calculator
Language	English