> Has anyone out there done any work interfacing to the TI 83 series of
> calculators? Any suitable reference material?

As someone else said, go to http://www.ticalc.org/pub/text/calcinfo/ and
down the bottom are a couple of zip files with info on the interface
protocol. It really is a nice simple interface that is non-speed critical on
either end of the interface, easily implemented, and simple.

Also look at the Piclink at http://sami.ticalc.org/ where there is some hex
code that you can disassemble to see an implementation of the interface.

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