TI calculators

I know that this is a bit far fetched, but a friend and I are currently making plans to do some crazy things with a link cord and TI82 calculators that they aren't designed to do... I was wondering if anyone knows the voltage and/or encoding used for sending data on the TI82. Asking here is worth a shot, I guess.

http://www.stud.uni-hannover.de/~sir...c/linkprot.htm

Looks like pretty standard RS232.

while we are on the topic of TI calculators, an idea came into my head about a year ago to design a kind of TI calculuator "hub."

I initially thought about using a normal 5-port ethernet hub. I thought about using the serial cable that plugs into a TI-calculator, and using that serial cable, buy a bunch of converters, such as a serial-to-parallel converter, etc., until i converted all the way into a networking cable, and connect that networking cable into the hub. The hub would then transmit data along to all the other TI calculators in the network, which would also be connected using the same converter method.

Its probably full of flaws, especially since i know nothing about networking, but it was just a simple idea I had because I wanted to play Tetrinet with some friends on a TI-calculator.

I havent tried it, of course...

Well, the serial bus itself is a point-to-point bus, there's no source or destination addressing. It might be possible to use some kind of bridge hardware to convert from the serial input to another kind of bus, and then connect all other devices to the secondary bus. Something like a PICMicro could handle the logic and the serial input/output, and then you'd need to buy some kind of ethernet controller IC and interface that with the microcontroller.

You'd certainly need custom software on the calculator end, too, but it can be done.