How to Make a Frankenstein 89 Graphing Calculator from a Ti 83 & Ti 89

One Methods:Alternate Method

With a few minor modifications you can swap the case of a TI-89 graphing calculator with a TI-83 case, allowing for use in classes where the TI-89 is restricted for its symbolic representation of variables, derivatives, integrals, plus many other features.


  1. 1
    Obtain a Texas Instruments TI-89 and TI-83 graphing calculators.
  2. 2
    Disassemble both calculators by using a Torx screwdriver.
  3. 3
    Take a Dremel tool (or manual file), and file down the 3 tabs in the case of the TI-83, where the TI-83's LCD display was held in position.
  4. 4
    As you have seen the hardware layout is a little bit different for each calculator. The previous step allows for the TI-89 into the TI-83 case. Fitting the TI-83 into a TI-89 case takes a little more work. Carefully, hold the calculator along with the LCD display to file the edges off. Be careful! This is a delicate process, so do not rush! Perhaps using masking tape will allow for strength so no connections are broken during this process.
  5. 5
    Fit the calculator guts back into their new shell.
  6. 6
    Swapping the pad from behind the LCD allows for a snugger fit in the Frankenstein-89. But will make the swapped 83's LCD move around, find some padding for a temporary replacement, and try a little non-hardening, clear-silicone cement when you are ready to make it more permanent.

Alternate Method

  1. 1
    Peel off the faceplate that borders the screen on both calculators and swap them. This method is effective because 99.9% of the time, the person who checks calculators just look at the logo on the upper right portion of the faceplate. This method is also useful in that the body of the calculator will still show the 89 commands/options (such as 2nd....) whereas if you switch the entire body, you are left with 83 commands/options printed above the keys.


  • Remember, even if your calculator can help you through the exam, you still should understand the math at the appropriate level for your understanding. Otherwise, those who think they are clever, and perhaps sneaky, will eventually need to demonstrate and invent methods which your Frankenstein 89 cannot compute.
  • TI89
    Keypad layout can become tricky as some keys do not match up. You can relocate keys on the TI-83 case, with those from the TI-89; this will make the user interface more friendly, but may also bring questioning into the calculator's validity.


  • Some courses will check your calculator before exams, bring a second tamper free calculator to show for inspection.

Things You'll Need

  • TI-89 Graphing calculator
  • TI-83 Graphing calculator
  • Torx screwdriver
  • Dremel or a hand file

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