TapBASIC Programmable Calculator

TapBASIC is a calculator programmable in BASIC with Dropbox integration. It has all of the familiar BASIC commands and it’s usage is only limited by your imagination. For example, problem solving, quadratic equations, physics, trigonometry, statistics and more.

Here’s what our users say about TapBASIC:

“Used PDAcalc on a PALM for many years, by far the best programmable calculator I have ever used. Since getting an iPhone, I have been looking for a suitable replacement for PDAcalc. I had not found any apps that were close until I tried TapBASIC. I had a question about the Dropbox integration and the developer answered it within hours. Very impressed and happy with the app.”

“I graduated from the Palm and needed a programmable calculator. This is the best. I adapted a thirty line program to calculate lens powers.”

“I am a freshman and I have finals soon. This app is great to check my practice problems! Thanks so much!”

“Works for me, easy programming, I wrote a formula to calculate my insulin for a meal bolus.”

“I made all my accounting formulas execute with user data so I don’t have to work so hard. Love it!”


  • Easy BASIC programming language: FOR/NEXT, PRINT, INPUT, WHILE/WEND, IF/ENDIF, CALL, CLS, DIM, REM and more
  • Variables and arrays
  • Broad range of maths functions and access to date and time variables
  • Graphing/graphics
  • Formatting and input options: decimal, hex and exponent
  • Debug and step through your programs
  • Dropbox integration
  • Email programs

Bug reports and feature requests: Feel free to leave a comment on this page or contact us on marovada at yahoo dot com dot au

Click to download the TapBASIC manual.

49 thoughts on “TapBASIC Programmable Calculator

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  3. The key() command does not work. It returns an “Unknown command” error message. If I run it in Debug mode it thinks key and () are two separate things.

    • Use ‘key’ instead of ‘key()’. Does this impact backward compatibility? If so, I can fix in the next update to use either ‘key’ or ‘key()’.

      • How are you using ‘key’? The syntax is variable=key. For example: j=key. In order to get the program to stop and wait for a key to be pressed, use:

        print “Waiting for a key…”
        while j=0
        print “Key pressed is “+j
        Rem use keyreset to clear the key value if you want to get another key later*

  4. I copied and pasted the example you just gave. When I run the program this is the results.
    ÅÅWaiting for a key
    I then pressed the number 5 key and the program showed
    ÅÅKey pressed is
    Number expected

    Those ÅÅ characters actually showed up there.
    They are ASCII character 143.

    I am using an Apple iPhone 4s with operating system 5.1.1

    Also in the TapBASIC manual the example for the for/next command actually shows the example for the call command.

    • Hi Bill. If you copy from this site you will likely copy html code instead of some characters. In this case it’s probably the quote marks ie “. Once you’ve copied the text into TapBASIC’s editor you can manually delete the quote marks and then retype them. Alternatively, you can hand type the program. You’re getting errors because TapBASIC doesn’t understand the html code for a quote mark.

      Thanks for pointing out the call example in the manual. I will fix it in the next update.

      • I did replace those characters with quote marks before I ran the program and it did not work. Are you test running the program on an iPhone?

      • Bill, yes I am testing on an iPhone. I copied the text from this site. Then I retyped the ‘…’ and each of the quote marks and the program worked perfectly. I suggest you follow these steps:

        1. Type a new program (don’t copy anything):


        See if you get any errors. Describe the erros. Then debug. Describe what happens when you debug.

        2. If you get no errors, type:


        Repeat error reporting/debug as per step 1

        3. The type:

        while j=0

        Report same as above

        4. Continue gradually inputting the program, step by step and report.

  5. OK, I tried that and the program worked. Now what if I run the program and want to enter a letter instead of a number. How can I do that with only the calculator keys available?

    • Bill, glad to hear that it worked. Right now, you could translate a number key into a letter eg:

      rem j is the ket press*
      if j=3
      print “a”
      if j=4
      print “b”

      I appreciate this is not ideal. There is not enough space on the keypad to have all of the letters. I’m going to look at programmable buttons for a future release. For example, assigning one of the number keys to a letter and displaying that letter on the key. Still, there is an issue with space.

      What are you attempting to do with your program?

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  8. Can an expression be used in the Dialog box for the Input/Ask command? For example: dividing or multiplying numbers.

    thanks, Mike S

    • Hi Mike. An expression can’t be used in the Ask/Input dialog at this time. I’ll consider including that feature in a future release.

  9. Hummm.. this has improved a lot..I kept away this app for months and I had a great surprise on this (major) update. Congrats for that. Finally, a programmable calculator for iOS.It must improve to be ‘must have’, but you’re on the way…
    I’d like to suggest a few features I couldn’t find in it:
    1- When Saving it should show the list of names in the path, before input the name
    2- Also when saving, names shoudn´t be case sensitive (and they’re!)
    3- When prompting characters they aren’t displayed properly (accents, currency symbols, etc)
    4- It should be possible to define by program the numeric format (at least, # of decimals)
    Thanks in advance,

    • Ramon, I’m very glad you like the new version and thanks for your suggestions. I’m happy to keep improving the app. Feel free to rate the app or write a review on iTunes :D

  10. Just purchased TapBASIC and wrote a simple program, it worked great. I uploaded the program to the PC via Dropbox. It is easier for me to edit the program on the PC, it there anyway to get it back down to TapBASIC on an iPhone?

    • Sure. Just download it from Dropbox in TapBASIC. Press the Dropbox button on the load screen and then press the folder icon to download it to your documents folder. Let me know if you have any questions.

      • I left one other reply about this. I only see a dropbox button on the documents screen. i press this and nothing happens. Would love to go back from dropbox to tapbasic.

      • Hi Rick,

        This means that TapBASIC is not linked to Dropbox. In the load screen, press the “Action” button in the top right corner. One of the menu items is link to Dropbox. Press that menu item and follow the instructions. Once linked to Dropbox, the ‘Dropbox’ button will work.

        Let me know if you have any other questions.

  11. Thanks for your quick reply. I am linked and have uploaded several small examples of code to Dropbox, which I can access on several machines. I now want to go in the other direction, to fashion code on the Mac (or PC) and load onto TapBasic on an Iphone5. I will turn the link on and off and see if that helps.

    From you previous comment it seems like I can expect to see the contents of the TapBasic Dropbox folder if everything is working. Looking forward to that!

    • Hi Gary, Bad news and GOOD NEWS. I unlinked Dropbox and relinked. The work email address associated with Dropbox changes passwords every 90 days. This is not the email address I am using here, if that matters. I updated the password. I created a new program and successfully uploaded it to Dropbox. When on the Documents page, with no file selected, if I press the Dropbox button, nothing happens. I also have TapBASIC loaded on an Ipod touch. SUCCESS! I got it working on the touch. I noticed that when I uploaded a file to Dropbox on the touch, the upload folder disappeared once the upload was complete and the file was still selected. The folder reappeared once the file was not selected. On the problematic Iphone, the folder does not disappear after the file is successfully uploaded to Dropbox while the file is is still selected. Powering off the iphone and repowering did not help. Should I delete the program and re-download from Itunes? The goal is to develop custom marine navigation programs on both devices and pass programs between them. Apologies for the bandwidth…

      • Hi Rick. What version of TapBASIC are you using? (Use the ‘Menu’ button then ‘About’ to get the version number). When you press the Dropbox button, you should briefly see a circle (indicating a network communication) in the top left of your iPhone screen. Do you see it?

  12. Hi Gary. When I press the Dropbox button, I see the circle on the Ipod touch, which works. I do not see it on the Iphone5, which doesn’t work. Both are version 2.5.

    • Rick, are you using ios 6 on both devices? When you click ‘Dropbox’, does the button label change to ‘Documents’? Try deleting and reinstalling the app. If this doesn’t work then I’ll send you instructions via email on what to do next.

  13. Gary, IOS 6.02 on fairly new Iphone5, 4.3.2 on older 2nd generation Ipod Touch. Everything works fine on the Touch, including the button changing from “Dropbox” to “Documents”. No circle when pressing Dropbox and no change to “Documents” on the IPhone5 IOS 6.02., before and after reinstalling the app. I hope this helps you if it is an IOS version issue. I would like to use the program on the Iphone someday, but no emergency, no fire, since I can use the touch.


    • Thanks Rick. I’m looking into it. If I have trouble finding any bugs I’ll email you instructions to install a special version of the app that can be used to figure it out.

    • Thanks for buying TapBASIC. Click the button with the blue folder icon to go to the load screen. Click the program you want to load in the list to highlight it. Then press the ‘Action’ button in the top right corner and select ‘Load File’. Feel free to let me know if you have any other questions.

    • There is no easy way to transfer files to and from your iPhone to your computer so a lot of apps use Dropbox to enable you to do this. For example, with TapBASIC you can write a program on your mac or pc and then test it on your iPhone using Dropbox. Or you could use Dropbox to collaborate and share programs with other users, your friends etc Dropbox gives you flexibility to use TapBASIC any way you want to.

    • It was easy to fix. Updates have to be submitted to Apple for approval. Hopefully they won’t take too long but it’s usually about a week or so. Unfortunately developers don’t have any control over this process.

  14. I’ve programmed basic since the late 70’s. TRS80, C64 and Quick Basic. This a mysterious syntax error that gives me a “expected number” error.
    Print “C = “;c;” uF”

    I’ve tried adding a + on front if the c variable with the same result.

    To get it to work I had to do this
    Print “c = “;
    Print c;
    Print “uF”

    That works with every other basic interpreter that I’ve used. What’s the problem?



  15. Hi Paul. I don’t sell TapBASIC in Australia because Apple would require me to register for GST even though my sales don’t reach the GST registration threshold. Registration for me would be costly. You can buy TapBASIC from US store.

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