.83i is TI bitmap file
Key Features: .83I File Extension
What is an .83I file?
The 83I file extension is associated with the programmable calculators TI-73, 82, 83, 85, 86, 89, 92 developed by the Texas Instruments. The .83i file stores bitmap picture.
It is viewable in popular XnView picture images management software for Windows and Mac.