I built this RTTY interface back in 1978. It allowed me to use my Commodore 64 computer to get on the air with RTTY and CW. I also was able to monitor commercial transmissions. It generally got better than 99% copy on W1AW bulletins.

I now have a Tigertronics interface which I am playing with. I like it but the CW is generated with an audio tone. I plan to post a fix that allows you to run full power breakin by keying the actual CW key line.