|Sigma, R/S, and functional grouping |
Message #10 Posted by Karl Schneider on 24 July 2007, 4:56 a.m.,
in response to message #1 by Richard Garner
Richard Garner posted:
The 35s is a nice size, it fits well in the hand... I would still have changed the Sigma and R/S keys.
I noted the same thing. The basic issue is functional grouping, a good thing which seems to have been followed here at the expense of practicality.
Sigma+ is a data-entry key that also belongs to statistics and probability. On the Voyager-series models (e.g., HP-15C, HP-11C, HP-10C), Sigma+ and Sigma- are adjacent to the main data-entry keys, and also grouped with the prob/stat keys on the bottom row. R/S is grouped on the left side with other keys for programming, such as GTO, GSB, and SST. R/S can be used to allow entry of data, but without prompting, usage is not very obvious.
However, on the programming-friendly HP-41, HP-42S, HP-32S, and HP-32SII, R/S is much more of a data-entry key -- used immediately following a number key. Hence, it took the place of Sigma+, which is seldom used anyway.
The HP-32SII and HP-33S use R/S for completing data entry in Equation mode, and with the INPUT command for programs. Sigma+ was placed on the top row along with the other prob/stat keys. This would have been worth preserving on the HP-35s. However, the cursor keys on the top row displaced the prob/stat keys, which were all moved toward the bottom along with Sigma+. R/S went to the upper-left corner along with other keys for programming. This is very much like -- the HP-15C!
So, the bottom line: Good functional grouping, but diminished practicality for this aspect of the HP-35s.