HP calculator geneology

[axd1967]

DM42 and Free42 triggered my attention to the evolution between 41-42-48.

As owner of an HP48SX (and also briefly of a 28S) I discovered its roots in the DM41 (a 41CX clone), and recently started digging in the User Manual of the 42S to discover how close these three calcs are related.

I searched for "evolution" but it looks like this is the only thread; I was also sent to
http://www.finseth.com/hpdata/evol.php.

'evol' tells following:

41C/CV -> 41CX
41CX -> 42S
41CX -> 48SX

With what I know for now (I'm still busy with the 42S manual), I'm much more inclined to believe following:

41C/CV -> 41CX -> 48SX
41C/CV -> 42S -> 48SX

or at least there has been much cross-pollination between 42S and 48SX

but of course the 48SX has also 41CX features such as alarms, so the 48SX is more a merge of various ideas.

I did not take the 28 or the 15 into account.

Here are my arguments:

1. The 42 misses 41CX features, as is also stated in the 42 manual
2. there are no significant 42 features that are not present in the 48
3. The 42 clearly improved the 41 UI, and the 48 further improved that UI (eg the evolution of the menu concepts)
4. The 42 manual layout is very similar to the 48SX. Now this sounds like a less objective argument, but to me this is part of the relationship between 42 and 48.
   

rgds