Re: Homeade Link Question
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Re: Homeade Link Question
The TI85 expects 11 on the wires. (both about 5 volts.) when the calc is
unconnected, or connected to open air, nothing gets modified, and thus the
11 the ti85 itself sends over the linkport (indicating rest mode) keeps.
However, the parallel port (probably serial as well) will take the 11 and
process it, effectively 'taking' the voltage and sending 00 back. Whenever
the calc is in Ti-OS mode, which is really WHENEVER ZShell is not running,
it will run various bits of code all the time (200 times a sec, actually.)
one of these is the linkport checker.. if this routine sees 00 on the
wires, it takes this to mean an external source like the CBL or another
calc has asked the attention, and will then stop whatever the calc is doing
and wait for data to come in and process.
To avoid this, fire up your link port programme before connecting. (one
specifically MADE for homemade stuff. ti85 graph link software will *not*
work.) these proggies initialize the port and make sure it sends 11 over
the channels connected to the link-port, and so your calculator will think
nothing is 'up'. Until you begin issuing send and recv commands from your
link program, in which case the calc will not respond properly and an error
occurs, -OR- the calc is in [2nd]-link recieve mode, in which case transfer
will happen.
If starting a specific homemade link program before connecting your calc to
your computer does not fix the problem, check the diodes. are they in
correct position? Any point which is positively 'stealing' the power out of
the cables can cause the problem... whatever manages to take out the 11
that the calc is sending but send back nothing (00, no volt on the lines)
will cause such a slow-down/complete crash until you remove the calc, which
will restore the 11 signal over the linkport.
--
-R.Zwitserloot@BTInternet.com
Geno Bisceglia <gmbst27+@pitt.edu> wrote in article
<33D45E14.3207@pitt.edu>...
> I built a link to use with my ti-85 to hook up to my computer, but when
> I insert the link into the calc, it slow down the calculator. Then I
> cannot send anything nor can I use any of the computer software.
>
> thanks
>
> gmbst27+@pitt.edu
>
References: