Definitely not a pocket calculator!


Hello all,

Given that a calculator such as the 48 Series and the 50G are definitely high-level and highly function-laden graphic calculators, would it've been possible to put the 48/50 series into a pocketable (Classic as its thickest baseline and Pioneer [42S] as its thinnest) form-factor?

I'm wondering because, having 28S, 48GX, 48SX and 50G and using the TI-36X Pro on a trial basis, I can see how the 50G's functionality could've been created in a pocketable form-factor and I wonder why the 48 and 50 are so large.


The limiting factors are the screen and the keyboard. Perhaps to a minor extent the batteries. The electronics are tiny these days.

- Pauli


Hi Matt,

about the 48G:

(1) low resolution screen

(2) lots of keys

It could have been kind of slim if it hadn't inherited the GX card slot housing.

I love it for (2) since I'm no fan of 'menu overload' (I'm also a fan of the 32SII just for this).

Edit: I also like the C= key monsters, starting with the SR4190R :-)

Edited: 3 Sept 2013, 12:19 p.m.


I wonder if it would work as a clamshell design: screen on one side, keys on the other.



I wonder if it would work as a clamshell design: screen on one side, keys on the other.

All the world hates a HP marketing found out a quarter of century ago.


I always wonder why HP thinks that a high-end calculator must contain graphic capabilities, and therefore, a large screen which makes it unpocketable. I remember an earlier post asking if forum members use graphic functions in calculator, and most of the reply seemed negative. Of course, a large screen is also good for stack viewing, matrix entry, etc, but to me I am eager to see less in favour of a smaller form factor.

WP34S is a good example of a high-end calculator with small form factor.


It is useful to be able to plot a function, e.g., before searching for a root or to graph the residuals from a statistical model fit. Something like the little HP-28s screen could be fitted in a pocket calculator. Its resolution was 137 x 32 pixels. With modern display densities this could be doubled and perhaps the vertical pixel count increased to provide the popular 16:9 format while keeping the screen area small.



But how many people really need that? Most times that I have a function that could be graphed, I know what the graph will look like (otherwise I probably wouldn't be using the function!), and I don't need to see it. I just need a numerical answer at some point.



It depends.

First, let us talk about the width/height. These are entirely governed by the size of the screen and keyboard. So, the more keys, and the more useable these keys are; and the larger the screen, the larger the calculator.

Depending on the specifics of the mechanical on these 2, you will need to add more or less some space around them to hold them in place.

So, this entirely up to you to pick the dimentions that you want based on what you can tolerate on these 2 components.

A classic HP rotate/click keyboard, due to it's mechanical does require more space around than other types of keyboards. The smallest keyboard would be the type of tactiles keyboards that you found in the 80's ( , ). Unfortunately, they suck. Then you have the typical membrane keyboards. You know the ones that feel like rubber... etc...

For the Thickness, you have a couple of factors there:
Thickness of the LCD. Unfortunately, because we are a company that needs to design products tested for robustness, and that need to survive a kid's thrown backpack, or a 1m drop on concrete floor, we have to stenghten the LCD. so behind the LCD, you will find an aluminium plate and some padding. This adds close to 2mm to the thinkess of the machine.
Also, because of the HP rotate and click keyboad, we also need to add quite some depth to the machine. first for the height of the keys, then for the travel and then for the thickness of the PCB behind in order for it to be stiff enough not to bow when the keys are pressed.
The last item in this stack is of course the battery. AAA are close to 1cm in diameter. in Prime, we decided to put a rechargeable battery that the user can change. These are thicker than Li-Poly AND require a battery door which itself takes some thickness.
Also, smaller batteries have less power and would not last as long...

If you look at prime, you get a good example of what you can get within these constraints.

So, as a summary, if you want a small calcualtor you will need to:
- Compromise on the size of the keyboard
- Use a keyboard with no tactile feedback
- Potentially reduce your battery life and changeability
- Reduce the product resistance to shocks

But let us say that you had the money to do it and did not care about these items, you could design a calculator with a metal structure ($, but thinner than plastic), a thin unprotected screen, a li-poly battery and a thin keyboard) and probably get to a thinkness in the 3.5-4.5mm range.

Cyrille, Musing


Thanks very much! I can understand the semantics now that the intricacies and technologies as well as why the technology is the way it is have been explained in detail.
Your post has helped quite a bit.


One pocket sized graphing calculator would have to have small keys, deep menu systems, and a small screen. HP attempted this with the HP 9g (ill-fated?). The most famous example of a mini-graphing calcualtor is the Casio fx-6300g. Neither the 9g or 6300 come close to the functionality of the HP 48/49/50 family.


As a matter of collector curiosity, the Radio Shack EC-4033 (=Casio fx-6300G) is a 2.8 inch by 5.5 inch graphic/scientific calculator with 50 keys. The graphics are quite limited.

Possibly Related Threads...
Thread Author Replies Views Last Post
  wp34s pocket reference Andrew Nikitin 48 8,333 08-11-2013, 06:18 PM
Last Post: Didier Lachieze
  WP-34s pocket reference Andrew Nikitin 4 1,390 06-12-2013, 12:27 PM
Last Post: Howard Owen
  The French TI Namir 4 1,061 10-13-2011, 03:20 AM
Last Post: Namir
  Yet another pocket RPL idea... bhtooefr 15 3,193 03-23-2011, 12:30 PM
Last Post: bhtooefr
  How about a pocket / hand held RPL calc? Michael de Estrada 54 7,835 01-28-2011, 07:15 AM
Last Post: Bart (UK)
  Why the resistance to make a true pocket Sci RPN calc Gerardo Rincon 10 2,065 11-15-2010, 01:20 AM
Last Post: Walter B
  EMU71 in my pocket and on my pad. Egan Ford 10 1,976 10-26-2010, 10:02 PM
Last Post: Raymond Del Tondo
  Pocket Professional Math-Pro Norman Dziedzic 1 783 04-12-2010, 05:03 PM
Last Post: Han
  Shirt pocket plotter for HP41 Wilhelm Taylor 3 1,058 03-15-2010, 11:44 AM
Last Post: Steve Leibson
  First Pocket Calculator with LED Display? Joerg Woerner 9 1,695 01-07-2010, 05:08 PM
Last Post: Frank Boehm (Germany)

Forum Jump: