[Pinus]

I, too, have a 28S that rarely sees the light of day. Instead it is my older, and much less advanced, HP-10C that gets occasional exercise.

The 28 and 48 series sat in a kind of awkward spot between pocket calculators and "real" computers. The programming language is essentially Lisp turned backwards, but for any task where you actually need that capacity, it must have been easier, even at the time, to just use a PC (in the wider sense, not just IBM PC and clones). The 48 had better communications facilities, so I imagine it might have been useful where pocket carry was actually necessary (it seems to have been popular with surveyors, for example, and I have seen them hooked up with a cable to a total station).

[Jtsummers]

The language is basically a hybrid forth-lisp. I liked it, sadly my HP-48G bit the dust a while ago and was not recoverable (water damage, lost a lot of things).

And it may have been easier to use a PC, but PCs aren't portable. The calculator could easily move with you. This is not a trivial matter when moving between desk and lab and the field. With today's laptops and smartphones a calculator like that is less useful compared to the alternatives. But in the 90s and 00s it was definitely handy.

[mschaef]

> it must have been easier, even at the time, to just use a PC (in the wider sense, not just IBM PC and clones).

Agreed.

It was probably a tradition dating back to the fact that HP did the original pocket calculator, but even through to the 48's, HP did literally all of the engineering. Everything from the physical design of the device down to design and fabrication of the custom CPU and other semiconductors. There was just no way that business model was going to stay competitive with PCs over time.

(While I'm reminiscing, however, I would've loved to see the RPL software running on a machine based on the HP100LX chassis and a faster CPU... Much bigger display, a workable clamshell design, and RS232/IRDA/PCMCIA expansion.)