Questions and Answers
		    (applies to all RPL machines)

As I read through the questions and answers section of the HP48
owner's manual, I found some ommisions so I am proposing this addendum
to address these.  Comments and additions from others would be

A: Support, Batteries, and Service


Q: When I press the backspace key I sometimes get an error message.

A: When you press the backspace key with nothing on the command line,
it performs the Drop function.  Drop is a function so it requires an
argument from the stack and returns no result -- thereby clearing the
bottom item from the stack.  So when you perform the Drop function
without an argument on the stack, technically you are committing an

Q: But sometimes I just press the backspace key out of habit before
starting a new calculation.

A: That isn't necessary in RPN(L).

Q: Yes, but I want to anyway and what harm does it do?

A: Well, it is an error to call a function without an argument, isn't
it?  If you really want to clear things out, press right-shift CLR,
this clears the stack without returning an error when the stack is

Q: Why does backspace give an error if CLR doesn't? Why not just have
neither one give an error?

A: Because Drop is a function and functions require arguments while
CLR is a command and commands don't require arguments.

Q: Are you insane?

A: This is a perfectly consistent approach, you're just not smart
enough to appreciate it.

Q: How come you can't edit equations in the Equation Writer application?

A: It's an equation *writer*, not an equation *editor*.

Q: Why are half the algebra functions in the Algebra menu and half in
the Equation Writer? To get anything useful done I spend hours going
back and forth.

A: The Equation Writer isn't really done yet, it will be completed in
the HP48SX's successor.

Q: Will there be an upgrade option?

A: No.

Q: Why not?

A: The same 178,000 inveterate geeks account for over 70% of our
sales.  If we started an upgrade plan, our dealer channel would
evaporate overnight like the morning dew.

Q: Whenever I store a number, it disappears just before I was about
use it and then I have to leave the menu I was going to use to recall
it again.

A: This is normal. It is part of the HP48's elegantly consistent
approach to handling functions. The STO function takes two arguments
including the number to be stored.

Q: Is there going to be another owner's manual?  In spite of its size,
this one seems oddly incomplete.

A: A more complete manual was considered but dropped. Partially due to
expense but mostly because market research shows that prospective
buyers of pocket calculators would find a 4 volume 3600 page manual
unsettling. Various geek organizations provide more detailed technical
information, support, and pointless speculation about the HP48.

Jeff Brown
Steinmetz & Brown, Ltd.
2675 University Ave
St Paul MN  55114
+1 612 646 2478



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I am Craig A. Finseth.

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Last modified Saturday, 2012-02-25T17:30:11-06:00.