TTY-Connect Teletype Interface System

The TTY-Connect Circuit Board

TTY-Connect provides everything needed for connecting most teletype machines in up to three local current loops, and for connecting a computer (PC) and/or a radio terminal-unit (TU) via RS-232 serial ports. Power is provided for the TTY loops (and current-limiting), as well as full opto-isolation. Note: this unit is NOT designed to connect to externally-powered loops.

You can simply use the unit as a loop supply for connecting multiple TTYs on a loop. Or, you can manually patch a loop to a computer's 232-serial (com) port, allowing a program on the computer to talk to the tty gear. Or, you can manually patch a loop to a radio terminal-unit's 232-serial port, and have the tty gear print the received rtty broadcast. Or, you can include the optional microcontroller to provide programmable signal connections between the loops/TU/PC, data-regeneration, and customizable features like Auto-CR-LF-Insertion, Autostart (motor powering), Selective-Calling, Who-Are-You (WRU), Ascii/Baudot-Conversion, Speed-Conversion, etc.

Note: This is not an entry-level project. You must procure the parts, assemble the circuit board, prep and wire a chassis, test high-voltage circuitry, and load firmware into a microcontroller. TTY-Connect has nasty lethal voltages inside -- please be extra careful. No warranties expressed or implied.

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Last updated: Jul 8, 2005 (format-only)