Re: TI-H: link port specs

To: <ti-hardware@lists.ticalc.org>
Subject: Re: TI-H: link port specs
From: "David Knaack" <dknaack@rdtech.com>
Date: Tue, 12 Oct 1999 18:05:53 -0500
References: <3803A46B.66BE687C@earthlink.net>
Reply-To: ti-hardware@lists.ticalc.org


From: Matthew Pirkey <mattymaximus@earthlink.net>
>     does anybody know the exact specifications for the ti link ports? Am
> i assuming correctly that they communicate at 9600 baud?

No.  Since there is no real clock, the data rate is in no way gaurenteed.

> what about actual signaling? is it RS-232 or somthing else?

Its something else.  The cable has a ground, red and white.  To transmit a
'1' bit, the sending calculator pulls one of the wires to ground (I forget
specificly which wire it is).  To send a '0' bit, it pulls the other wire to
ground.  The receiving calculator acks by pulling the other wire to ground.
After the ack, the lines go back up, and the next bit is sent.

There are documents with more details on the signaling and protocols in the
TI-Files archives (enough detail to allow you to write your own file
transfer program if you wish).

ASM programs have implimented other protocols too, I2C for example.  Without
a real clock RS-232 would be difficult (at best).

DK

Follow-Ups:

Re: TI-H: link port specs

From: Grant Stockly <gussie@stockly.com>

References:

TI-H: link port specs

From: Matthew Pirkey <mattymaximus@earthlink.net>