Minimal Key Calculator

[rprosperi]

(03-13-2015 08:32 AM)Didier Lachieze Wrote:  

(03-13-2015 08:17 AM)Gerald H Wrote:  In another thread the question of unnecessary functions & redundant keys is raised:

http://www.hpmuseum.org/forum/thread-3345.html

What could be the least number of keys needed to reproduce all the functions of, say, the HP 35S keyboard?

If you were happy with a purely binary calculator, only two number keys would be required - but probably you would want to keep decimal input, so let's say you stay decimal.

With 16 keys you can have the complete HP 41CX function set:

Didier - could you please post a larger, hi-res scan of that, or point out where it may be found if already online somewhere. It looks mightly interesting, even if all it does is answer the topic of this thread, however I'd guess it does more than that. Thanks.