GO-21 SciRPN 4+

Stephen Lidie

    • 5.0 • 1 Rating
    • $2.99

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.

• RPN (Reverse Polish Notation)
• 10-digit LED calculator display, 10-99 to 10+99
• Four stack registers with roll down
• One storage register with arithmetic memory operators
• Math, trigonometric, polar/rectangular, logarithmic, power and other miscellaneous functions
• One additional window with views of:
◦ stack/storage registers
◦ keystroke log
• Copy-from and Paste-to the calculator display

What’s New

Version 6.6.3

- Miscellaneous improvements recommended for everyone.
- Update for MacOS 14.4.

Ratings and Reviews

5.0 out of 5
1 Rating

1 Rating

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.

Dhjdhj ,

Hate that high visibility setting

To me, the value of this app (and all the other RPN apps that I have) is the authenticity of them. Otherwise, there are a gazillion calculators with different sized displays out there with RPN.

Instead of making the X view high visibility, why not enlarge the calculator itself to be full screen (even getting rid of the stack view optionally)

Then I’ll go back to 5 stars again which otherwise this app absolutely deserves.

Developer Response ,

For some thoughts on sizing, see:

https://www.bigcatos.com/BigCatOs/go-2x-scirpn/go-21sizehistory.html

The App seems to be sized as authentically as possible. The stack view is and always has been optional, simply hide it forever, as described in the documentation.

The High Visibility Display setting is optional and disabled by default so you never have to see it, thus the calculator remains in its pristine state. This option has been requested by two groups of users: as an Accessibility assist for those with diminished vision, and folks who use the App outdoors as part of their work.

Rbollo53 ,

50 years later - Thank you

Many thanks for giving me the opportunity to use this RPN calculator. I bought my very first HP 21 C in 1972 when studying at Polytechnic School of Cameroon. 50 years later, I am still very happy and proud using RPN devices and programming Common LISP.

App Privacy

The developer, Stephen Lidie, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More

Supports

  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

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