LF: Re: 92<->Modem Link!!

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LF: Re: 92<->Modem Link!!

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> From: that1guy@juno.com
> To: list-fargo@lists.ticalc.org
> Subject: LF: 92<->Modem Link!!
> Date: Wednesday, November 20, 1996 9:22 PM
> 
> I just had this idea for a homemade direct 92-modem link...
> If you go on to ticalc.org and click on "links and link software" and
> then get the instructions on how to build a serial link for the ti-82,
> do you think that would ALSO convert the ti-92 data to serial??? You
> know, it's so simple it just might work!!! If it works on the 82, why
> not the 92? Heck, the parallel cable works on both!
> 
> If anyone has this cable, or builds it up to try, please let us know!!!
> 
> that1guy@juno.com






I haven't seen it but think about this:  Serial ports communicate at 9600
baud (and higher and lower) at 10 volts. Parallel ports communicate way
faster at 5 volts.  TI calculators communicate at 9600 baud  at 5 volts!
This means you either must convert a serial port signal into one for the TI
calc or find a way to make the parallel port work with the calculator. The
reason the latter is done and not the first one is because TI calc's don't
communicate at exactly the way computers do. The spacing or bit length
could be just slightly off and therefore a special chip is needed (and a
lot more money to buy a Graphlink).  The parallel link works because the
parallel port doesn't actually understand what is going on. It justs gets a
lot of Ascii 0 and 1 characters (That's what happens when you communicate
serially with parallel lines, think about it).
References: