HP had an excellent calculator application software, running on the limited HP 100LX/200LX palmtops.
Although a little business oriented (I suppose it is similar to the HP 27S), it included logs, trigs, plotting, solver, stats, 4-model curve fitting, lest from date calculations, TVM, amortizations... Oh, it also accepted both algebraic and RPN modes. It lacks programability, complex mode, matrices, symbolic math, base conversions; but is very usable and friendly, at least for engineers that became managers like me :-)
As I had stated in this Forum before, when the first Windows CE machines appeared in 1997, I expected HP to announce a model which a good calculator application. I could not believe when the WinCE based HP 300LX appeared... and the "calculator" feature was a very basic Windows 4-function calc! Needless to say, I was much dissapointed because of that step back from the 200LX.
If HP had such good calculator application in 1994, running on a 8086-class, 7 MHz chip with 1 MBy RAM, and even made it multitasking on a MS-DOS 5.0 environment, the only reason for HP not doing something comparable for a current PDA is that HP does not believe it makes sense (for them) on a business perspective.
On the other hand, if you see the HP home page, where a legal settlement notice shows how HP had to spend a lot of money in reimbursements and lawyer fees due to a supposedly misleading Jornada advertising, you could understand that HP may be reluctant to announce any new product or software that may lead to such situations. For collectors, an "allbugs" machine is a dream, but the business rules of today make a big financial problem from any imperfection.
I know I am getting too nostalgic for old times, but sometimes I wonder if the HP 35, (with some initial bugs), or the HP 41 (with its bugs and weak contacts), or, for that matter, the almost perfect HP42S, with its PERM and COMB bug, could be announced today without being subjects of lawsuits; instead of being the functional marvels they were at their time...
Just in case, I am not affiliated with HP in any way, and have no position or interest on the Jornada claim.