Thanks for the info. Do you know if there is a specific software it uses? I'm guessing not stuff like DM780 and such, being they're for soundcard modes. Thanks!
Ooh, I dunno what all is in the "Franklin Converter", I thin if you look at some 80's and 90's era articles about SSTV and WEFAX stuff you will find that it is similar and has some dedicated decode or encode hardware for such modes, before PC's commonly had sound cards.
Really, for a soundcard interface, you don't need much. I had been slightly involved in RTTY back in the 1980's but I abandoned all that old stuff long ago. When I got on for RTTY roundup in early 2012, my "interface" was nothing more than alligator clips between PC sound card connectors and rig connectors, and have since made some better (more permanent) cabling.