Screenshots

Description

GO-21 SciRPN simulates the venerable HP-21 Pocket Scientific Calculator from 1975. Virtually indistinguishable from the real item in operation, GO-21 is a powerful yet simple retro calculator.

GO-21 combines the classic behavior of the HP-21 with modern iPhone capabilities like key click sounds, visual touch feedback, persistent stack, memory and display format, and help information.

• Requires iOS 8.0 or later
• RPN
• Copy / Paste
• Shake to clear X
• Swipe gestures that roll and display the stack
• Addition, subtraction, multiplication, division
• Trigonometric functions : sin, cos, tan, sin⁻¹, cos⁻¹, tan⁻¹, degrees or radians
• Rectangular/polar coordinate conversion
• Logarithmic functions : log, 10**x, ln, e**x
• Other functions : Y**x,1/x, √x, π
• Display : LED, 10 significant digits (8 + 2 digit exponent in scientific notation), 10-99 to 10+99
• Memory : 4 register stack, stack roll down, X-Y interchange, manual memory with register math
• floating stack and memory window

What’s New

Version 4.13

- Update for iOS 12.0.
- Do not raise the stack when using the EEX shortcut immediately after an ENTER.

Ratings and Reviews

5.0 out of 5
6 Ratings
6 Ratings
NanoRon ,

Lean & Mean

I’ve been using this app for a number of years and have been very satisfied and figured it was time I gave it a review. As an engineer, I loved my HP-21 and was sad when it finally died many moons ago. I searched and searched for a simple reverse Polish calculator app, but could never find a good one. This is a good one. A clean but elegant emulation of a classic design. Highly recommended.

lbartosh ,

My thoughts on the HP 21 app

I have an hp 21 that we purchased new and I've always loved it, not only for the RPN feature but for the simplicity. This is such a nice app for anyone familiar with the HP line plus it shows the stack. Highly recommend.

Noneblank Nickname ,

Return with us now to the days of yesteryear

I bought an HP-21 during my third semester of college in 1976. At that time they were still teaching students how to use a slide rule.

The app is a very good reproduction of the HP-21's look and functions/functionality. I has the functions I want and doesn't have a lot of functions that I don't use. It has a useful Help file.

Information

Seller
Technology Man IR
Size
26.5 MB
Category
Utilities
Compatibility
Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.
Languages
English
Age Rating
Rated 4+
Copyright
Copyright (©) 2009 - 2018 Stephen O. Lidie, All rights reserved.
Price
$0.99

Supports

  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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