Thats some very helpful info! Thanks a million. I didnt realize there were TTY Tone Decoder chips. Do you have any info on those? I think it would just be easier for me to use the tone decoder chip and process the data through the PIC, instead of making the PIC do all the work. Trying to "Descriminate" the audio levels are gonna be a bit unreliable. I am aware that a computer can be used to dial-in to the Relay Service, but a phone line isnt always available, and all that can be found is a payphone headset.

Also, any ideas on what i can do about a small keyboard? Ive seen really cheap palm keyboards for 15 bux, think that can be used on a PIC? I would like this thing to be as small as possible, so no full AT keyboards... hummm... unless i build the terminal INTO the keyboard...