August '13 Thomas Henry TI-83 uC interface

[ahagele]

Hi,
I'm trying to get into this little exotic project of connecting the old TI calculator to a PIC micro.
And as mentioned in the article the workings of the actual link is a bit of a challenge.
I have only a TI-89 not a TI-83. And a USB link cable. That means I can't use that mentioned terminal program and I don't get a virtual serial port on the PC to run a terminal program.
I got the PIC software going and can do test programs there.
On the TI I was using the SendChat command to send data to the port. But I don't get anything into the PIC and TI just comes up with communication error.

I wondered if there is a simple terminal program for the TI-89 that would just send out one byte at the time. I've tried a few terminal/chat programs but they all seem to do far too much for what I need.

Or is there another simple way to test the basic bit and byte transfer?
I'm planning to get the oscilloscope involved soon, but it's not available right now.

Thanks for your help.
A