HP-51G: Back to the honorable roots!


HP has brought back the HP-15C... Is there a chance for influence the design of future products?---

Just a quick sketch of my 'dream design' for the Model 51G, HP's serious and powerful answer to TI-Nspire CAS etc. and the graphical RPN/RPL/... reference calculator for the next generations of (machine/computer/space/financial/...) engineers and scientists:

My recipe for HP: * Take the outstanding quality, the robustness, and its timeless 'beauty through simplicity' of the HP-15C(LE), think of the HP-71B! * Enlarge the keyboard (red: shift to alpha characters, the other (empty) keys in my sketch have to be reorganized). * Preserve the low power-consumption design by considering the use of e-ink technology for a hi-res display (four or sixteen shades of grey, unfortunately color e-ink seems to be a technical problem). * Preserve the IR interface and the serial port, add a HP-IB option. * Use the high-quality OS of the 48/49/50 series and offer HP-41 compatibility. * Needless to say: Add some more memory than in the HP-50g.

BTW: What is a color multi-touch Android "iPhone-ian" WiFi 3G GPS ... hardware with only nine hours stand-by time e.g. in field use worth?

Looking forward to a new legend,

Martin Paech

(Please excuse my awkward use of English.)

Edited: 9 Apr 2012, 3:43 a.m. after one or more responses were posted


I like it except for enter key placement. I'm an old guy with too many ingrained habits.




Reminds me of my very early keyboard designs :-) but a little bit more layouting and label rearrangement seems necessary. Come on!


Edited: 8 Apr 2012, 2:59 p.m.


Far better already :-) But it's a pity you edited your original post so we cannot assess the development (such backward editing is next to "Geschichtsklitterung", please stay away from it). Still there are two blank keys top right, however. And you are a bit too lazy keeping all the original label links of the 15C IMHO - think about shuffling and redistributing labels for optimum layout results. BTW, you cleared the original label CLEAR which made some golden labels meaningful at all ;-)


:-( I am very sorry for my "Geschichtsklitterung", a side effect of replacing the file of my first sketch an my website (unused) polygraphie.de that led to an actualized image in the original post. Tomorrow I have access to the source computer and I will post the first version again.

Indeed, I'm a bit "lazy", but my thesis is calling for my attention and I've to salve my conscience... The 'L(A)ST x' and the 'RAN(DOM) #' labels are "lost in reorganization", too, and the missing 'CLEAR' label leads to a really funny result!---Please, be patient with a german "Gr√ľnschnabel" (= greenhorn). ;-)

Edited: 8 Apr 2012, 6:55 p.m.


Why soft keys to the right instead of under the screen?

Not enough mechanical space around the screen. It can't go that far to the edge.

Why lose a key position for a decorative "51"mark?

Again, too little space at the bottom, between keys and edge.

Get the programming keys out of the way of computations. Look at the 48G keyboard for inspiration.

I know you simply used a 15c for the keys, but many of those commands make no sense. If it is a full-powered graphical, then why would "FIX SCI ENG" get prime real estate?

Without a preliminary design for the operating environment, the key layout isn't really sensible.

You'll never get everyone to agree :-)


Yes, all of you are right! My (very first) "design study" has weaknesses nearly everywhere and most of the key labels are totally senseless on the HP-50g successor...

But I hope by and large you get the "spirit" of a serious and timeless machine beside these new-fashioned but crude TI Nspire CAS or buggy iPhone apps etc. Unfortunately, I have to finish my Ph.D. thesis in the next weeks, so I cannot invest currently more than the 30 minutes for my sketch this morning.

The of course a bit simple-hearted question behind: The community has achieved the HP-15C Limited Edition. Does anyone see a chance to gain influence in the design and the quality of the next generation of HP calculator products?


Hallo Martin,

There are chances to influence HP design and product policy - you named one example yourself. Another one is the HP-35S five years ago. And the colours of the HP-50G. And perhaps more. But don't overestimate: the community may have influenced the design to some extent, but not in a direct way (else R<>P wouldn't be missing in the HP-35S, the HP-50G would feature a regular ENTER key, etc.). Thus a little fraction of the community became impatient and frustrated enough to start the WP 34S ... d:-)

BTW, which kind of Ph.D. are you doing?


Not bad for 30 minutes! (translation: actually 87 minutes total haha)

Good luck with ur Doctorate!


I like very much that it's not in "landscape" arrangement. "Portrait" allows for a much more logical positioning of the ENTER key...which I think should always be located in a column with and above the /x-+ keys. That column must, in turn, be either fully to the left or to the right of the keyboard.

(Please excuse my awkward use of English.)

One can not excuse what is not apparent. The natural ease with which all of the non-native speakers of English on this forum write never ceases to impress me. I unfortunately have little talent for the acquisition and effective use of foreign language, after some attempts with German, Spanish, Dutch, and Latin.

Edited: 6 Apr 2012, 12:30 p.m.


I like very much that it's not in "landscape" arrangement. That allows for a much more logical location of the ENTER key...which I think should always be located in a column with and above the /x-+ keys. That column must, in turn, be either fully to the left or to the right of the keyboard.

How could not be agree with you, Mike.....


Very interesting! I wonder how some of your ideas would fit in with a modified version of the HP 39gII which appears to have a higher resolution display, more flash, fast CPU, low cost, high performance architecture? By combining your color scheme, an existing chassis and the ideas of this community, wouldn't the results be spectacular? It may not be entirely the desired result - but having any increased chance of actual realization is a feature to appreciate.


How about an emulator for this multi-line display baby???



I like this form factor. Throw in the trademark horizontal 1-1/2x wide ENTER^ (yes, with the up arrow). at the third (or fourth row) and you've got a deal!

You really should send that design to HP. I think it's a winner!

Curious though. What do the solid red and solid black keys surrounding the f & g prefix keys do?

Edited: 6 Apr 2012, 4:53 p.m.


The red one is for the alpha keys, while the black is for the OFF command, or probably just a memorial to the HP67 third shift key!!
Isn't it, Martin?

Edited: 7 Apr 2012, 10:14 a.m.


a memorial to the HP67 third shift key

Nice one! I like it.
And what about the 5 shift keys on the HP 67CX? :-)


And what about the 5 shift keys on the HP 67CX?

Oh yes, that stays unexcelled :-)


All my respect for the gorgeous 67CX design and its designers! But, in the MIL version the 'fire' command shouldn't be shifted and a 'yield' key for nuclear weapons should be added (see 'Lance Missile ROM Module' for the HP-71B). ;-)

@ Walter B: I did my Ph.D. research in Theoretical (solid-state) Physics (development and optimization of an algebraic-diagrammatic calculation method for a special perturbation theory, parallelized implemented in the good old ANSI C on my good old HP-UX PA-RISC J6750 workstation).

Edited: 7 Apr 2012, 1:15 p.m.


No, the black keys are are simply unlabeled up to now. For my first quick'n'dirty layout I re-arranged the HP-15C keyboard with Photoshop, and most of keys are still not on their final position. Moreover, a lot of the labels are not necessary on HP-50g's very different architecture with its complex menu system etc., of course.

Currently, I have only very limited time, so cannot work out the details of "my" HP-51G, especially of the keyboard. (Concerning its layout five people have at least seven opinions, anyway... ;-)

To complete my 'design study' notional, bear the HP-48S/G and the HP-28C/S keyboard in mind and combine it with the legendary (pre-)Voyager or the HP-71B design.


BTW: What do you think about my thought-provoking impulse for HP to use an e-ink hires/grayscale display with very low power consumption (instead of a color LCD)---to the benefit of a faster CPU and more (and faster) memory, e.g. for data acquisition?



BTW: What do you think about my thought-provoking impulse for HP to use an e-ink hires/grayscale display with very low power consumption (instead of a color LCD)---to the benefit of a faster CPU and more (and faster) memory, e.g. for data acquisition?

really I appreciate it, but keep in consideration please (in this project I mean), what here said about the position of the enter key, thank-you very much!

Edited: 7 Apr 2012, 2:34 p.m.


E-Ink and similar technologies do not yet have a high enough refresh rate that they work well for things like cursors. In addition, they have priced themselves out of our market.

The 39gII has a 4 level greyscale screen and the device pulls 4ma at idle from 4 parallel AAA batteries. It also has 128MB of flash, although only 512KB of RAM on the CPU.



> 512KB of RAM on the CPU

Sounds pretty much like the RAM that the Saturn can access in the 50g :-)

Like I said around a half year ago: With some minor effort by then we would have

a successor of the 50g by now.

It would not be as "shiny" as somebody would expect but it would be better then

what is there *today* - with minimum effort.

All that is needed for it is there (and even more) - it would show
that HP calculators still wants to play in the professional league.




P.S. Gotta talk with my shrink about my biting reflex ;-)

Edited: 10 Apr 2012, 8:23 p.m.


And, he asks plaintively, where (or when) can I get one?!?!




Would it be locked up tight by the designers like the TI nspire or open like the 71 or even completely rewritable like the new HP's 12, 20 & 30b? It's not like we'll ever see it but while we dream, lets dream about a calc that can fix it's inevitable rev-a flaws.

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