|Re: Which scientific calculator? (HP-15C)|
Message #19 Posted by Karl Schneider on 2 Apr 2009, 5:56 a.m.,
in response to message #13 by Mike Morrow
The facts are that it is very slow, it lacks the precision of later models,
The 1982 HP-15C has the same processor as the 1979 HP-41 (albeit "declocked"). The faster Saturn processor, programmed for 12-digit results, did not appear in RPN models until 1988. Six years was a long time to wait for an affordable RPN alternative to reserving time on the mainframe or buying an expensive, primitive early PC.
it is *very* awkward to use while holding in the hand (absolutely insane for a "hand-held" calculator!),
But it's superb for desktop use, with the user's hand moving in a natural side-to-side motion, instead of back-and-forth. The display is moved closer to the user with the calc near the edge of the desk -- as with students, and engineers before they had PC's with pulled-out keyboard tray on their desks...
it has very limited memory,
More than the base HP-41C (and more than the successor HP-32S/SII)...
The 64 allocatable and 3 non-allocatable registers (two used for matrix indices) made it possible to invert an 8x8 real-valued matrix.
it is non-intuitive to use without referral to the manual when dealing with advanced built-in functions (especially matrices),
I disagree vehemently with that -- espcially when one compares usage of SOLVE and INTEG with that of the HP-42S. Linear algebra on the HP-15C requires the user to perform more manual steps, but these are methodical and logical. It is important that the HP-15C user understand linear algebra.
I rarely if ever need to consult the HP-15C's excellent manual. One exception would be inversion of a 4x4 complex matrix -- better to use an HP-42S or RPL-based model for that. But it can be done on an HP-15C...
it has very limited display, it has no alphanumeric display,
It is what it is, but the display is easy to read...
Needless to say, this topic has come up before: