|The superb HP-15C (adding to archived post)|
Message #1 Posted by Karl Schneider on 15 June 2003, 3:01 a.m.
Valentin Albillo wrote nice short essay in the Forum (3 June, 2003) extolling the HP-15C. I've been meaning to expand on parts of it as a reply, but it's already gone to the archives. Here's a link to his posting:
Voyagers rule ! [LONG]
I bought my 15C in late 1983, and it met my needs through three university-degree programs. Only in the last 15 months did I fill out my HP collection with 12 other models. The 15C is still probably the one I'd take to an exam, if I were allowed to bring only one calculator. It's that capable and useable.
Now, if the HP-11C is amazing, the HP-15C is simply unbelievable, the best pure calculator in the world, hands down. It has everything the HP-11C has, and much, much more.
An excellent HP Journal article about the development of the HP-15C, written by Dr. William Kahan in 1983, is available on the MoHPC CD-ROM/DVD-ROM set, and Dr. Kahan's website. If "pure calculator" implies non-alphanumeric, I'd also agree with the "best in the world" assessment. Otherwise, I'd give the nod to the 42S, while conceding that the 15C has some advantages -- e.g., more-legible display, quick keyboard access to all functions.
Further, everything was so well (thought through) in its design .. You felt there were no arbitrary limitations at all .. All features were integrated and complemented each other perfectly, most served for several apparently unrelated purposes.
Exactly! The 15C is a masterpiece of thorough, meticulous engineering, not only in the construction, but the up-front design of algorithms and functions. The engineers packed an impressive amount of functionality onto a keyboard and display that lacked the expandability of named functions and menus, and yet made it all intuitively logical. The detailed, error-free manual is thicker and heavier than the calculator, but I believe that most users, after initially learning how to program and to use the advanced functions, need not consult the manual (or the supplementary Advanced Functions Handbook) in order to perform tasks using the 15C.
I also agree about the lack of "arbitrary limitations" -- something I see in the direct-successor 32S/Sii and the 20S. The 32Sii has less user RAM, and lacks the matrix functions and complete, integrated complex-domain functionality that were specifically provided in the 15C as a design objective. The 20S provides certain functionality of the 15C as "loadable" programs that require usage-instructions and wipe out the contents of user RAM. Both products seem "stripped down" in that respect.
The 15C, by contrast, is "right-sized" -- it has enough resouces and built-in functionality to tackle any problem you'd reasonably want to try on a handheld calculator. Practically anything it can't handle would be better attempted on a PC with the appropriate software. Of course, the 41CV/CX and 42S are better for extensive programming than the 15C, which wasn't really indended for those purposes.
The dual-purpose keys of the 15C were ingeniously intuitive. For example:
-- nPk and nCk keys [statistical permutation and combination; or, "partitioned" and "complex" matrices]
-- I and (i) keys [indirect addressing of registers/labels; or, imaginary (complex) numbers]
-- 1/x [reciprocal or matrix-inversion]
There's never been anything like the HP-15C, there never was before, and there never will be in the future...
Alas, probably so. Modern high-end calculators compute faster and have more fancy capabilities, but I'd doubt that any are as thoroughly well-executed as the 15C. It's more than a still-useful tool; it belongs in a "Hall Of Fame" of consumer electronics.