Re: Richard Nelson's pictures of the 4 HP 15c versions

The capital C stands for 100 in roman numerals, which is about the relative increase in speed of the new 15C's compared to the old ones. For me it should therefore be a capital C (still) much like the V and X represented the memory-increase (in roman numerals) of the 41CV and 41CX models compared to the 41C.

"C" in HP calculator convention stands for continuous in terms of memory. The first models were not able to maintain the memory once they were switched off. I am not sure whether the HP-19C/29C or the HP-25C were the first to have the continuous memory feature. Apparently, this feature was a big enough differentiator for the marketing guys to use the C for the HP-41, the voyager series and even the HP-28C. Yet later, with the HP-28S which got more memory the C has been abandoned, and only S (for scientific) and B (for business) survived in the more recent models.

And I speculate that the C was in upper case because CONTINUOUS was a big deal then and it hat to be shouted loudly ;-)

Possibly Related Threads…
Thread Author Replies Views Last Post
  HP-80 Teardown with pictures Max Stone 10 3,837 10-24-2013, 09:10 PM
Last Post: Walter B
  DIY543 pictures Richard Ottosen 93 22,767 10-22-2013, 08:04 AM
Last Post: Cristian Arezzini
  RPN-1200 (with pictures) Benoit Maag 12 3,881 09-02-2013, 06:09 PM
Last Post: Matt Agajanian
  HP Prime pictures with video ! Mic 55 12,443 06-24-2013, 02:52 PM
Last Post: CompSystems
  HP-41 New versions of your favorite modules - with an AOS twist :-) Ángel Martin 13 6,696 06-21-2013, 01:29 PM
Last Post: Diego Diaz
  New pictures of HP Prime in hand Mic 52 13,516 06-15-2013, 10:15 PM
Last Post: Peter Murphy (Livermore)
  New screen on pictures of new Sharp EL-9950 Mic 4 2,080 06-10-2013, 10:40 AM
Last Post: Mic
  HP-65 Repair/Restoration (Pictures) :) Dan Lewis 8 2,930 01-12-2013, 12:41 AM
Last Post: Dan Lewis
  PCB pictures of a HP10B, HP20S or HP21S? Christoph Giesselink 1 1,142 12-17-2012, 10:19 PM
Last Post: Randy
  DM12CC in pictures Ingo Paschke 0 1,059 07-15-2012, 06:54 AM
Last Post: Ingo Paschke

Forum Jump: