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0 stars out of 5
30 ratings

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5 stars out of 5
· 4/26/2015
Great RPN calculator

The perfect RPN calculator. Works perfectly. Full keypad and keyboard support. A pleasure to use.

5 stars out of 5
· 9/23/2014
Excellent little calculator

I love the size and shape of the calculator. I can snap the app to the side and use it easily with other apps. Some functions require getting used to (x^y requires the user to input the exponent before the base), but otherwise it works beautifully.

3 stars out of 5
· 6/21/2014
Not bad, but problems with error trapping

This calculator is cleanly laid out and easy to use. The macro feature is a nice addition, and is easy to figure out even without a help screen. It inherits the HP35's inability to warn of an overflow error. Just remember that 99.999E99 is "infinity-overflow." Also, remember that the trig functions work in degree mode only. More annoyingly, division by 0 always yields 0. The original HP35 would also display zero, but would flag the error by flashing the display. That feature is missing from RetroCalc. I would give RetroCalc a higher rating if div/0 were flagged (since that feature existed in the original microcode), and if the inherent limits (i.e. overflow, no radian mode) were explained on a help screen.

5 stars out of 5
· 12/9/2012
1972 was A Great Year

I was an engineering student at Univ of Wa in '72 and my mother bought this calculator for me. I became very popular because a lot of students wanted to borrow it for homework. Mine is Serial No. 1249A05378. Reverse Polish Notation (RPN) is way more efficient!

5 stars out of 5
· 11/13/2012
great RPN calculator

I love this calculator. It snaps great on the surface tablet. It has programmable scripts. The red led display takes me reminds me of my old HP. This calculator has all the essential functions and shows you the full stack. Great app.

5 stars out of 5
· 11/3/2012
Best calculator app I've found

Nice app for those who enjoy their RPN calcs. Fits well snapped to the side of the screen. Very easy to use. Recommended.

4 stars out of 5
· 10/1/2012
A good RPN calculator with just the basics

For those of us that were weaned on RPN and just want the most important calculator functions, this is a very good choice. Its only downside is that in trying to keep very close to the original HP calculator color scheme, it is unattractive. It really needs copy and paste functionality so values can be shared with other programs.

5 stars out of 5
· 9/27/2012
Fun retro calculator

This takes some time getting used to. But the old UI grows on you. Very helpful for side by side multi-tasking. It has all the functions I need and the ones I don't. I ran into zero bugs. I enjoy using this part of history. 5/5

5 stars out of 5
· 9/27/2012
Fantastic RPN calculator

I wasn't sure I'd find a good RPN calculator already, I'm pleased to see it here. It works beautifully and looks/works great docked. I sorely miss using my HP 42s and it's not practical to carry it around. color coding is nice. layout is different than I expect but can get used to it.

5 stars out of 5
· 9/18/2012
An awesome piece of history!

When the HP-35 came out, it was the first ever handheld scientific calculator and immediately supplanted the slide rule. This emulator is running the actual ROM bits from 1972. To this day, RPN is still the most elegant way to work. I have the original device on my desk and use it every day. The only features I've ever wanted are being able to see the whole state of the device and to be able to program it. Now, with RetroCalc, I can see the stack and memory registers and can record formulas!

stars out of 5

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