RPN 28x Calc - FAQ

Math can be fun.

1 General Questions

1.1 Which version do I have?

For 1.x and 2.x versions, the version number is shown in the bottom right corner of the display. You may need to squint a little to see it. If you were unable to see it, you can select "Email Your Feedback" from the action menu in the top right corner. The version number is mentioned in the text of the email.

Beginning with version 3.0, the version is mentioned at the top of the info menu; press the (i) button to see it. As before, the version number is also mentioned in the text of the email that generated if you select "Email Your Feedback" or "Compose a Mail with Your Suggestion".

1.2 Can I run it on a Mac with Apple Silicon?

Yes. However, you will only be able to see the iPad-style interface. Also, I am told that keyboard support is not currently working.

1.3 Can I use an external keyboard?

Yes. Support for an external keyboard was added in Version 1.3.

Early reports indicate that keyboard support is not enabled when running the app on M1 Macs (macOS on Apple Silicon).

1.4 Why does "30 SIN" produce "-0.988…"?

You are operating in radians mode (RAD); the "2-pi" symbol is shown at the top of the display. To change to degrees mode, tap the "2-pi" symbol or execute the DEG command; the "2-pi" symbol will disappear. Now "30 SIN" produces "0.5".

2 User Interface

2.1 I cannot see the new XYZ button

For instance, version 3.5, added the "CONVERT" button. Where is it?

If you cannot see the new button, then you may have used button reordering in an older version of the app. When the new version reads your custom button order settings, it will read only use the buttons that are stored there; it will no attempt to merge these settings with any new buttons that may have been added.

To access the new button set, you will need to discard your custom button reordering. Sorry. You can discard your custom button order settings by selecting "Reset" on the button reordering line in the settings window.

2.2 How do I open or close the assistant window on iPhone?

Since version 3.5, the assistant window can also be accessed on iPhone. Tap the "page ear" in the top-left of the display to open or close the assistant window. Tap the "down" or "up" arrow in the top-right of the viewer to enlarge or reduce its size.

In the assistant window, you can inspect the log, your variables, and browse the catalogue of pre-defined scientific units and constants.

2.3 How do I clear the command log?

The log is limited to 512 entries, above which the oldest entries will be removed.

Beginning with version 2.1, you can clear the log manually. Swipe upwards in the log viewer to reveal a card with action buttons.

Using the selector on the left, you can limit your actions to:

  • All Entries,
  • Today,
  • Recent (i.e. a day earlier than Today), and
  • Not Today.

To delete the entire log, select "All Entries" and press the trash can icon.

To email today's entries, select "Today", press the share button and select Mail in the action sheet that will appear.

2.4 What is meant by "Recent" in the command log selector

Basically, it selects entries that were added "on a day before today". If you were using the app every day, that would be the same as "yesterday". If you were using RPN 28x Calc only on Sundays, then for you, "recent" would mean "last Sunday".

3 Known Issues

3.1 App Crashes After Update

When upgrading from version 2.x to 3.0, it may happen that the app crashes during its launch cycle. You may see the app launch image and then nothing more.

This is due to a bug in version 3.0 when trying to decode data written by version 2.x.

Prior to the release of a fix, you can avoid this scenario by deleting the App from your device (and also deleting all of its data), and re-installing it from the App Store. Note that this will delete any variables and all values that you have had on your stack.

3.2 Support for Complex Numbers

Support for complex numbers was added in version 3.4.

To enter a complex number, begin with a parenthesis, and enter one or two numbers after it, separated by a space or by the operand separator (e.g. "," when your decimal separator is ".").

You can operate with complex numbers in the same way as with regular numbers. You can even mix regular with complex numbers for most computations.

3.3 Support for Matrices (arrays of arrays)

Support for matrices was added in version 3.0.

In pre-3.0 version, arrays of arrays are not supported. You may see a side effect of this when you add an array to the statistics array with the 'Σ+' command. What happens then is that the array is unpacked and its elements are added to the statistics array (which is purely one-dimensional).

3.4 Very large numbers in FIX mode

Update: This has been fixed version 1.1.

When the FIX number formatting mode is enabled, then very large numbers may be too large to fit the screen and they will appear scaled and truncated. The corresponding number is intact, it is merely displayed badly.

4 Contacting tredje design

4.1 How can I become a beta tester?

Simple, please contact me.

4.2 When will RPN 28x Calc become available in my language?

Since all calculator commands use English names or abbreviations, it is not meaningful to create different versions for other languages. There are therefore no plans to create non-English versions of this application. Sorry.

4.3 I think I found a bug. What should I do?

Within the app, you can select "Email Your Feedback" from the (i)nfo menu. If you like, you can save the message as a draft (tap Cancel, then Save Draft) and continue editing it from within your email program.

Feel free to write your message in English, German, or Swedish.

Alternatively, you can send an email to tredje.bugreport@mailnull.com (don't put this address in your address book as it is temporary), or use the online contact form.

The following information would be helpful:

  • Which version of RPN 28x Calc are you using?
  • Which iPad do you use?
  • Which version of iPadOS or iOS is installed?
  • If it crashed, what was it that you were trying to do when it happened?
    (Please sync your device with the Finder (or iTunes) and include the crash log: ~/Library/Logs/CrashReporter/MobileDevice/*/Calculator-*.crash).

4.4 My question is still unanswered. What can I do now?

Why don't you post your question on this contact form?