fin@norge.unet.umn.edu (Craig A. Finseth) (05/07/90)
This is posted for (and written by) a friend of mine, Jeff Brown of Steinmetz & Brown, Ltd. Replies sent to me will be forwarded. ---------------------------------------------------------------------- As I read through the questions and answers section of the HP-48 owner's manual, I found some ommisions so I am proposing this addendum to address these. Comments and additions from others would be welcome. A: Support, Batteries, and Service ANSWERS TO COMMON QUESTIONS 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 error. Q: But sometimes I just press the backspace key out of habit before starting a new calculation. A: That isn't necessary in RPN. 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 empty. 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 HP-48SX'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 HP-48'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 HP-48. ------------------------------------------------------------ Many (:-)s. Craig A. Finseth fin@unet.umn.edu [CAF13] University Networking Services +1 612 624 3375 desk University of Minnesota +1 612 626 1002 FAX 130 Lind Hall, 207 Church St SE, Minneapolis MN 55455-0134, U.S.A.