Hi,

Use a microcontroller with large flash memory and SRAM.
(The 16F84 should be considered obsolete).

Start with the decoder part HW and SW.
(Receiving data is the difficult part of this project).


1. Using the PC freeware, generate the TTY/TDD tones with
the PC sound card at 45.45 bps. (Baudot @ 45.45 baud = U.S. TTY/TDD).

2. Decode the TTY/TDD tones from the PC with your HW decoder chip.
(Example of decoder chip: XR2211, Exar Corporation).

3. With the microcontroller take the output of the decoder chip
and display the data in ASCII format on the LCD.

Best regards,

Luciano