TI-H: RF/IR-link protocol

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TI-H: RF/IR-link protocol

  Perhaps the most compatible (and _simplest_:):):) way to do any sort of
a link is to work it so it's identical in function to a direct-wire
connection - we don't have to use any sort of special protocol, so that
anything using the regular link will work with this one as well.
  Of course, the question is: how?


  The answer has already been stated on this list.  Use two different
frequencies of light/radio, one for the red wire, one for the white wire.
Whatever comm system any program sets up will work.
  Just to clarify:  The regular TI-OS sends a bit by pulling one of the
wires low; the red is a 1 and the white is a 0 (it might be backward...),
and the remote calculator confirms by pulling the other wire low,
whereupon both go high again, calc #1 first, and the process repeats.
  Probably some game programs just send data in serial or along a clock;
the RAM expander, for example, uses one wire (I think it's red) as a clock
to regulate transmission, while the other wire modulates it both ways.
  In other words, anything else, and the calculator's own OS can't handle
data transmission - which means RAM backups can't be sent, because the
program would overwrite itself!  (The normal system is in ROM) - and all
existing programs would have to be re-written, to be more complex, more
buggy, and bigger.


  So something like a "wireless extension cord" is our best bet.  Just
thought I'd mention this, before we go off on a tangent.




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