Appendix D: Common Errors - HP -65 Owner's Handbook Manual

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Appendix D
Common Errors
. Having unwanted duplicate names (labels) for user defined
functions in memory because [f was not pressed
in W/PRGM mode before keying in a program.
. Inadvertently erasing a program in memory by inserting a
magnetic card when W/PRGM-RUN switch is set to RUN.
. Inadvertently erasing a program on a magnetic card by in-
serting an unprotected magnetic card when W/PRGM-RUN
switch is set to W/PRGM.
. Keying unwanted operations into program memorybecause
the W/PRGM-RUN switch is set to W/PRGM when keys are
pressed.
. Failing to shift up to a gold function ( [fl or ) or down
to a blue function ([8]) because prefix key was omitted.
. Losing the T-register contents because the entry of a new
number or the recall of a register lifts the stack.
. Destroying the contents of register R, because a trigono-
metric function, a relational test, or the rectangular-polar
conversion was done.
. Failing to take account of a merged code and to provide a
NOP as filler in a two-step skip.
. Performing a trigonometric function in the wrong angular
mode.
Mistakenly trying to call user defined functions labelled (o],
...,[e].oniy. ...,B can be used to label or call de-
fined functions.
Forgetting to clear flags before using them.
Expecting, stack, or registers to remain unchanged
after calling a user defined function from the keyboard
(letters " e, E) or within a program.
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