Several weeks ago, I joined the relative few who own a complete set of HP Voyager-series calculators -- the 10C, 11C, 12C, 15C, and 16C. (The "KinHPo" 12C Platinum is not included in this set, nor do I intend to purchase one.)
The last and most difficult one to obtain, of course, was the 10C. Introduced in 1982 and discontinued in 1984 -- presumably due to poor sales and lowered prices -- the supply of these is quite limited, and high prices are the result. For a functionally-perfect and cosmetically excellent 10C on eBay, I paid the price of a 15C in a similar state. I hadn't seen too many offered on eBay; the opportunity was enticing.
The 10C, I'm sure, was an attempt to fill the price/product niche of the entry-level scientific model, much as the 31E and 32E models did for the Spice series. (One can infer that the 15C was the successor of the 34C, and the 11C similarly replaced the 33C).
Where HP erred with the 10C, I believe, is omitting useful functions in order to provide rudimentary programmability. It's as though HP considered it unthinkable not to fully exploit its Continuous Memory technology by producing a nonprogrammable scientific calculator. Instead, they foisted off a substandard product that only the unknowledgable and the budget-conscious purchased.
The programmability it offered was the simplified paradigm also built into the finance-oriented 12C -- no insert/delete editing, no labels, no subroutines. The most a user could enter was 79 lines of unstructured programming, displayed as numerical keycodes. And yet, in the 10C User's Manual, 40 of the 125 pages are devoted to programming! (By contrast, the 15C User's Manual had 293 pages.)
The 10C, with only one shift key, had a limited number of keyboard positions. Ten of these were allotted to functions pertinent only to programming (GTO, R/S, PSE, SST, BST, P/R, MEM, x<=y, x=0, CLEAR PRGM).
I believe that the HP-10C might have been a viable quality "entry-level" product as a nonprogrammable calc with more mathematical functions -- like a modernized 32E with Continuous Memory and one shift key. I have an idea what it should have been, using the contemporary Voyagers, Spices, and other previous models as guidance. I'll save that for later...
See also an archived thread: The Complete Voyager
-- KS
Edited: 22 Feb 2005, 3:43 a.m.