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HP 12C Calculator Application

Yep, we're live. If you downloaded 1.7, you should immediately upgrade because it used the wrong format for storing programs. You'll also need to install the OI File Manager to save and restore the programs.

Documentation in RpnCalc Pro Programming

There are a few useful programs in Useful RpnCalcPro programs, but they're not documented yet.

Anyway, give me your feedback on the new calculator. Until it's had a little more testing, I'm not ready to call it hp12-compatible.

-ed falk

Having been thru this process making your original financial calc a "HP-12c" equivalent, do you think it would be easier making the scientific one a "HP-15c" like?
 
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Having been thru this process making your original financial calc a "HP-12c" equivalent, do you think it would be easier making the scientific one a "HP-15c" like?

I'm giving it some thought. Because the hp15 can handle complex numbers, it means re-writing pretty much all the code. I was able to create the programmable calculator by building on top of the basic scientific calculator and build the financial calculator by building on top of that (love those object-oriented programming techniques.) I wouldn't be able to do that for the hp15. On the other hand, recycling the existing code for complex numbers won't be too hard.

I'll have to give it some thought. It's more likely that I'll tweak the existing calculator to give hp11 capabilities, and come back for hp15.

I'm hampered by the fact that to properly write an emulator, you absolutely must have an original device on hand to validate against. My hp15 was stolen years ago and they're selling for something like $250 on eBay.
 
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I'm giving it some thought. Because the hp15 can handle complex numbers, it means re-writing pretty much all the code. I was able to create the programmable calculator by building on top of the basic scientific calculator and build the financial calculator by building on top of that (love those object-oriented programming techniques.) I wouldn't be able to do that for the hp15. On the other hand, recycling the existing code for complex numbers won't be too hard.

I'll have to give it some thought. It's more likely that I'll tweak the existing calculator to give hp11 capabilities, and come back for hp15.

I'm hampered by the fact that to properly write an emulator, you absolutely must have an original device on hand to validate against. My hp15 was stolen years ago and they're selling for something like $250 on eBay.

Yeah going for the 11c first makes alot of sense. Especially since its replicating alot of the stuff you currently have in your own scientific calc, and using alot of the new stuff in the financial calc. OO does rock.

The nonpareil emulator is pretty awesome for "real" testing.
 
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I really love this app. I really wish the interface was more visually like an HP12c. More photorealistic. I think a whole lot more people searching the market for RPN would see their old 12c in software form and snatch it up. It would also help me visually as the contrast between the buttons and the calc face is better on the real calc.

thanks.
 
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Hi all; I'm the author of RpnCalcPro. It doesn't have the same layout as the HP12C (I intended to use it in portrait mode), but it has all the same functions except for programmability. It's $5 at present. More info at RpnCalc Pro

I've gotten some feedback from people asking that I make they layout exactly like an HP12 in landscape mode, so I'm working on it. It's a little tricky because an android screen is much smaller than a real HP12, so squeezing it all in is rather difficult. I have it working now for the Archos, and with a little tweaking, I can get it to fit on G1 and Droid. Look for the new layout soon.

Since I have a number of interested people here, I'd like to do a quick user survey:

Do you use the programming functionality of the HP12? I haven't seen a need to add it to the calculator app, but I might if there's a demand.

Do you find the HP12's n,i,PV,PMT,FV functions ambiguous? That is, do you have trouble knowing if the key will enter a value, or compute it? (I added a "Find" key to my calculator to remove the ambiguity, but maybe it's not needed.)

Also: the cash-flow calculations (Cf0, Cfi, etc.) Do you ever use these? Do you edit the stored values? Do you change the Ni values?

Other differences between the android app and the real thing: I have 20 memories, whereas I think the real one only has 10. The stack has 16 levels instead of 4. Statistics have their own registers rather than being stored in the main memory registers. I'm going to guess this doesn't cause anybody problems.

In general, I'm interested in whatever feedback you might have.

-ed falk

I definitely use the cash flow valuations for the calc, as well as the npv and irr functions. I also like using the n, i, pmt etc buttons for calculations! would love to see them! thanks
 
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Please emulate the original HP 12C as closely as possible with ALL the features that the HP 12C has. The latest update as an iPhone app has added many new features which are great. I use the basic functions as well as the financial functions. I use the loan amortizaztion features of the 12C the most but I also use the cash flow, IRR, NPV features occassionally but they are definately important to me.

You've probably already looked that the latest Apple app. I consider the app to be superior to the actual calculator. Having to give up having the iPhone HP 12C app due to moving over to an Andriod phone is something I will miss a great deal.

I'll purchase your Android HP 12C app when, and if, you are able to emulate or improve on the HP 12C.

Moving away from the iPhone due to AT&T's bandwith issues in my Houston market.
 
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Looks like another 12C app on the Market. MxCalc 12c. Its very expensive compared to other apps on the market.

Alot of 3gr's other android apps on the market are actually web apps, although this one at 1.70MB might actually be a genuine app. Can't really tell without buying it. The side effect of a webapp (amongst other things) is its dreadfully slow, which for a calculator makes the whole idea kinda pointless!?

Given the excellence of RPNCalc Pro, I'm not sure I'm going to buy it. Anyone had a look at it? Is it a real app & not a web app?
 
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Oh, by the way, programming mode is on the way. Look for it within the month. I'm thinking of selling two different versions, with programming and without. But maybe that will create too much confusion.

I have just found this forum. Great discusssion. I have been a HP12C addict since 1990 or so. I live in Canada and interest rates here are quoted as semi-annual compounding. We cannot use the "12./." function key but we have a programme that we can install in the 12C that allows us to just enter the annual interest rate, push R/S and it will convert to the correct monthly rate and automatically input that result into the "i" key. Obviously the programming feature will be very attractive to Canadian 12C users. :)
 
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Hi all; I just thought I'd check in with an update. The calculator is now called RpnCalc Financial and the documentation is at RpnCalc Financial.

You'll find it to be completely compatible with the classic HP12. Currently, it supports all the functions of an HP 12C and is fully programmable. If you install OI File Manager, you can also save and restore programs. In fact, the programs are hand-editable if you like. Just copy them from sdcard, modify them, and put them back.

It's the top-rated financial calculator on the Android Market. In fact, go to the finance applications and you'll find it there on the first page.

Thanks to everybody for their requests and feedback while it was under development.
 
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