HP Forums

Hi there. I've enjoyed the HP Museum for many years but never had a reason to post until now.

I'm a huge fan of HP calculators and RPN and I also happen to be an iOS developer. I just finished up development of a major new iPad / iPhone app, Tod Calc, and I need some help testing it. Tod Calc is a calculator app that you can customize to your liking. You can change the layout, function, color, font, and style of the buttons and display. Naturally it has RPN (I also included algebraic mode to accommodate the average user).

So, if you have an iPad or iPhone, I'd be happy to give you a free copy of the app if you will give it a try and then give me your thoughts about it. My goal is to make Tod Calc the absolute last calculator you'll ever need to buy, because you will be able to recreate any calculator from the past -- or create calculators of your own design.

Here is a page with screenshots of the app: http://tod.fm/tod-calc

Here is one reason this is such a powerful concept. I, like many RPN users, wanted an RPN calculator on my iPod. There are a lot of recreations of, say, the HP 12c. They work great. But the buttons are all really small. I wanted something like a basic, everyday RPN calculator with buttons big enough to be useful. Just the essential functions.

I actually made that app (it's called Simple RPN), but Tod Calc takes it a step further. Within one app, you can have a simple RPN calculator with big buttons, or switch to the HP 45. Or something completely different.

This first version of Tod Calc has a lot of features. It took a lot of effort to get it to this very usable, functional, and polished stage. But it could do even more. Here is a wish list of features, for those who want to test Tod Calc. I'd be grateful to know which ones you would value having sooner than others. I'm a solo developer, so unfortunately I have to do the most important things first just because my time is so limited.

- RPL

- Time calculations (it already has date calculations)

- Unit conversions

- Programming

- Parentheses (for algebraic mode -- useless to me, but maybe not to you?)

- Financial functions

- Statistical functions

- Probabilistic functions

- Anything else I'm missing?



Thanks,

Tod

Edited: 7 June 2012, 9:04 p.m. after one or more responses were posted

I can test for you on iPhone 4 and iPad 3, but I should warn you I am a developer with buried ambitions towards producing a calculator app someday (or equation evaluator). Or just publishing an app :)

I normally use m48 as my calculator on my iPhone and m48 with Starship skin on my iPad, and use m48+ with the 49G running when I need more power. (At my desk I use my 15C or these days WP34S or pull out the 50g for more power.)

I do collect calculator apps so I am familiar with a lot of them - Some I have include 42s, 15C, PCalc, powerOne FL, Soulver, Calcbot.

Looks pretty cool! If I ever win an iPad in all the drawings I enter I'd like to try it. For me I'd like to create a calculator that had all the common functions I use in electronic design. It would be nice to be able to have easily accessable and appropriately named storage for variables (e.g. i, e, f, R, C, L, etc.) and have dedicated buttons for frequently used impedance and network calculations.

Good luck with the concept and the product!

Hello!

Your calculator looks very promising. I volunteer to try ist out :-) (can't resist playing with calculators...)

For me, time calculations would be a very useful feature to add, even in a very basic way like the HMS+ key of the hp-67 (ideally unshifted). A couple of user-defineable conversions maybe, again on unshifted keys.

Regards

Max

Edited: 7 June 2012, 8:39 p.m.

I sent you a promo code via email.

Thanks very much! Just contact me through my web site when you get your iPad. I'll be glad to give you a promo code.

I sent you a promo code.

One of the issues with adding some of the more advanced features is deciding on the implementation. For example, to accommodate the two most common memory systems, I included M+, MR, etc. buttons, as well as STO and RCL. You could actually create a calculator with both... which would be strange. :)

With statistics and financial functions, for example, I have to think hard about how I decide to implement them. Either I provide a compatibility option (such as, Choose statistics mode: HP 12c, TI-30 etc). or just choose one way to do it. "One way" is basically the Apple way in general, which makes it easier for the user. Of course, doing it "one way" means being stuck with the junky calculator they put on the iPhone... which is the opposite of what Tod Calc aims to be. So it gets complicated in a hurry.

But, that's why we have updates.

Also, I just wanted to mention that if you press and hold on a memory register, you'll get a preview of the value of the register. Not in the calculator display, but in a separate popup.

Tod, I'd love to help. Can do an iPad2, original iPad, and iPhone4.

I'd like to help. I have an iPhone 4 and an iPad 3 (or whatever it's called).

Tod, would be happy to test as well. iPad2 and iPad1 available.

Thanks,
bruce (bruceb at fatcity dot com)

Please count me in too. I've got a 3rd gen ipod touch running iOS 5.1.1

Hi,
does it also support complex numbers? I would like to test it on my iPhone 4. Btw, this is the fist time I thought that the "i" in "iPhone" might indicate the imaginary part.

Would you consider porting or helping to port the WP-34S firmware to the iPod/iPad/iPhone platforms?

We've already got an extremely comprehensive feature set, good numeric stability and comprehensive keystroke programming support.

- Pauli

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- RPL

- Time calculations (it already has date calculations)

- Unit conversions

- Programming

- Parentheses (for algebraic mode -- useless to me, but maybe not to you?)

- Financial functions

- Statistical functions

- Probabilistic functions

- Anything else I'm missing?

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- Anything else I'm missing?

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Complex numbers.

Matrix support.

Physical and mathematical constants.

Advanced mathematical functions.

Number theoretic functions.

Integer mode (HP 16c style).

Solve and integrate.

I/O.

Decimal reals -- few people want binary real values in a calculator.

Most importantly of all, numeric stability and accuracy. Several of the functions you mention are rather difficult to implement well. A calculator must give reliable answers before anything else.

Have you seen the ancient Calculator Construction Set that was available for 68k Macs? It allows users to customise and create their own calculators broadly following the line of the 41c series.

- Pauli

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Complex numbers.
*can live without them*

Matrix support.
*not a big deal*

Physical and mathematical constants.
*we know those we need already*

Advanced mathematical functions.
*can't care less*

Number theoretic functions.
*WTF?*

Integer mode (HP 16c style).
*progrmmers' cut*

Solve and integrate.
*so-so*

I/O.
*that's a real miss, a show stopper*

Decimal reals -- few people want binary real values in a calculator.

Most importantly of all, numeric stability and accuracy. Several of the functions you mention are rather difficult to implement well. A calculator must give reliable answers before anything else.

* I am surveyor, so don't take me seriously (unless you have a real problem with your dearest achievement like your home)

Every one has their own vantage point and this is what I see from mine.

;)
*

Have you seen the ancient Calculator Construction Set that was available for 68k Macs? It allows users to customise and create their own calculators broadly following the line of the 41c series.

- Pauli

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I'd like to participate in your testing. iPod 4 and iPad available. I use Free42 / 42S, and have some others in my devices: a couple of 48 emulators, a 12c, a 21, etc.

email: "andres.c.rodriguez" (at) gmail . com

Edited: 8 June 2012, 8:51 a.m.

I'd love to see a WP-34S iOS port.

Ha! No, no complex numbers yet. That might be an RPL feature. I sent you a promo code anyway.

Unfortunately, it uses GPL 3, which prevents it from being distributed on the app store. By the way, I completely support GPL 3 and any free software I release would be under that license. Anyway, I've got a number of projects that I HAVE to do first...

Frido,

I/O isn't as hard as it sounds. The calculator definition files can be saved and shared, so in the future, other kinds of data could be as well.

What would you want to print? What would your ideal printout look like?

I do know about the Tod in German thing, which was pointed out to me, ever so conveniently, by a German guy I was skydiving with! "Tod" is just another version of the name "Todd", both of which are a Middle English word for "fox." I named Tod Calc as I did not out of egoism, but to try to give some kind of recognition to the brand "Tod" on the app store. It's purely marketing, which is something that I have to learn how to do, unfortunately.

You can call me "fuchs" if it would be more comfortable!

That's a great list. Thanks.

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Most importantly of all, numeric stability and accuracy. Several of the functions you mention are rather difficult to implement well. A calculator must give reliable answers before anything else.

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I agree completely. That's why I implemented a standard scientific calculator first, with RPN, and of course the customization engine.

It wouldn't be a serious tool without complex numbers and matrices. I guess I misjudged what the advanced users would need most. I don't do work that requires me to use most of these functions, so I have to rely on others telling me how important it is to be able to have this stuff.

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Have you seen the ancient Calculator Construction Set that was available for 68k Macs? It allows users to customise and create their own calculators broadly following the line of the 41c series.

---

I have only heard stories of this program of which you speak. Do you know where I can get it? I have a Mac Plus I'd like to try it on.

I sent promo codes to all the people who requested them so far. I hope you find the app as useful as I do, even though it doesn't have complex numbers.

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What would you want to print? What would your ideal printout look like?

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"Printout" sounds too limited. Maybe better to generalize its meaning by a "kind of visualization" beyond the relatively simple display you have at hands in a calculator. Possibly, you will also be able to emulate graphing calculators, and there is the point where visualization applies best to the function the calculator should provide.

I would like to visualize (printout) results of calculations, listings of programs or simple graphics like function plots, all feasible with ASCII, all for documentary purposes. If you have these as PDF, you may transfer it to a real printer or keep it as a file.

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You can call me "fuchs" if it would be more comfortable!

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Quote:

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"One way" is basically the Apple way in general...

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But the basic premise of your calculator is that there are many ways to design one.

I think the standard response here will be along the lines of "great! Could you please add ***?" the possibilities are endless :)

By the way, could you please add a programming mode? :)

I just went ahead and bought it. It's my general policy to buy any soft calculator that does RPN, as long as it's not outrageously priced. A buck for your efforts is peanuts. :)

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...in German "Tod" means death.

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That's the very first thought that came to my mind!



Have you considered the low probability that the typical Apple customer, wanting every aspect of device usage to be controlled by AppleGod, would be even mildly interested in your proposal?

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Unfortunately, it uses GPL 3, which prevents it from being distributed on the app store. By the way, I completely support GPL 3 and any free software I release would be under that license. Anyway, I've got a number of projects that I HAVE to do first...

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I realize it is off topic, but it would be equally awesome to see a WP-34S running on Android...

Jake

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I realize it is off topic, but it would be equally awesome to see a WP-34S running on Android...

Jake

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This should be addressed by Olivier :-)

Günter

The GPL license isn't an issue. We're willing to license the software under other terms and have already done so for portions of it for HP.

- Pauli

How do you envision this working? But perhaps a separate thread is needed...

I'd be glad to help in my non-existent spare time :)

Well, thank you! I hope you find it useful to be able to arrange the keys how you like...

I found my dusty old version. email sent.

- Pauli

Hi Tod!

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I sent you a promo code.

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Thank you very much for that! Over the weekend I played a little with the calculator. This is exactly the app I would develop if I had the means to do it (I have only two indestructible G4 PowerBooks and the SDK for apps requires an Intel processor...). Your calculator has almost 90% of what I will ever need.

Essential additions (for me) would be:

- Keyclicks or other sounds for feedback.

- Time calculations. Ideally automatically invoked by pressing the hour:minute:second separator instead of the decimal point. I have a little Casio calculator (LC-403LU) that does it that way. It would be important that the seconds are optional (either by adding a third and fourth decimal place as on the HP67 or by pressing the hms-separator another time) and that it can count beyond 24 hours and does not jump to "days" instead.

That would already allow me to configure it as my "ideal four banger" (as discussed here a few years back - the colon-key in the lower right is the HMS separator):

Desired additions:

- Fully user defineable key labelling (e.g. I don't like "FIX" for the number of decimal places but prefer the "DSP" of the vintage HPs instead, but right now, the app only lets me choose between FIX in capital or lowercase letters).

- Display the shifted function of the key labels all the time. Either in small lettering on the labels or in the gaps between the keys.

- User defineable function keys for conversions. Either simple constants that will multiply the displayed value by a factor or (better) keys that execute a formula. Just like the "A" to "E" label keys on the top row of vintage HP calcs. The calculator does not need to be fully programmable to do that!

Nice to have additions:

- A Background picture instead of the current patterns.

- Multi-Line display (ideally the whole stack in RPN mode)

- Other display types (like Panaplex or green CRT or Nixie...)

Until now, I have not dscovered any real bugs but will of course report them to you asap in case I find some.

Looking forward to the next version (which I will certainly buy!),
regards,
Max

Edited: 11 June 2012, 7:22 a.m.

Yes, it is definitely a nice app.
My observations so far:
It has way too many (decimal places). You can enter very many digits, the font size becomes smaller so that everything fits in the display, but as a HP user, I would expect that after a fixed number of digits (10 or 12), keyboard entry is disabled. If a calculation results in many digits, change from fixed to scientific notation and round some decimal places off.

Another thing I didn't understand: what happens if a key is pressed for a long time? The keystroke seems to be canceled, but there also appears a textfield. The expected behavior is to cancel the keystroke.

All in all a nice looking calculator. It will take me some time to find the preferred positions for the commonly used buttons, but the flexibility is great. I like the voyager-style layout best!

A couple of issues I've noticed so far:

1. Shift takes too long to update the keyboard - there is quite a long pause after pressing shift before the keyboard is redrawn.

2. Key entry isn't properly disabled by some functions - begin to type a number, hit roll-down, now you can extend the newly displayed number!

3. Sound feedback on keystrokes would be good.

4. Visual feedback on pressing Enter would be nice - HP's typically are left-shift during entry, right-shift on display - this seems to always be left shift?