Re: LZ: Link Protocol


Re: LZ: Link Protocol

I tried the talk85 program with the gray link cable connected to my computer
running Procom.  The computer displayed the data (characters ) from the
calculator, and the calc displayed the characters from the computer.  Now it
didn't work perfectly, there were some strange things showing up on the
calc.   For the most part,  it worked fine...

Someone (the author maybe) could modify the talk 85 program into an ANSI
terminal program.  There you go,  modem communications...

At 04:15 PM 12/9/96 -0800, Marty Williams wrote:
>I have some information I'd like to share with this group.  The topic of the
>info is the gray link cable made made by TI.  I know it's hardware, but
>please bare with me for a moment.  You may find it very interesting.
>I bought the link cable from Staples last week.  So,  the hacker that I am,
>I ran a terminal program (Procom), connected my calc, through the link
>cable, to com 1.  I then tried to send something from the calc to the
>terminal.  I managed to display the packet from the calc on the screen.  
>The packet was in raw ASCII format. When converted to hex, it was the same
>as in the Protocol Docs for the TI.  I had the terminal set to monitor mode,
>9600,N,8,1.  All hardware handshaking is off.  So then, I connected a
>protocol analyzer between my compter running TI's link program amd my calc.
>I sent a group file of everything to computer.  The protocol analyzer was
>set to auto setup.  I was able to see every packet sent between the two.   
>The protocol analyzer returned the following setup:  
>Protocol:  Charater
>Code:  ASCII 8
>9600 bps
>Party: none
>Async: 1
>LSB first
>I opened every pin connection in the link except for the following pin numbers:
>1: shield ground (may not need this)
>2: TX
>3: RX
>7: Signal ground
>20: DTR
>The link cable is being power from the TX line.  I traced it through a
>diode, caps, then to a small voltage regulator and then to the VCC pin on
>the microcontroller.
>Well, some of you may have known this info already or not.  Anyway,  you
>folks are the ones who can use this info towards writing com programs for
>the 85 or 92.   Only two things are needed to make the  gray link cable the
>interface to a modem or any other RS 232 type link,  power and software.  
>I'm planning to try one of the chat programs next, with my terminal program
>and the 85.  It will be interesting to see what happens.  I'll let you know
>what I see.
>So...what do you think?