Plug and Play! Load software, Plug in MFJ-1275MX to your computer/transceiver and enjoy operating modes like PSK-31!MFJ's ConnectionWizard easily connects you transceiver to your computer's sound card for operation of PSk31, RTTY, SSTV, PACKET, AMTOR, CW, HSCW meteor scatter, Contest Voice Keying and other modes that require a sound card. No more unplugging or manual switching for operating different modes with one radio!MFJ's PSK/Bypass switch lets you choose normal operation or digital mode with a switch! In bypass mode, your MFJ-1275M provides normal station operation with microphone audio, PTT, and VOX. In PSK mode, microphone audio and PTT can be interrupted at anytime 0 this is great for SSTV or Voice keyer. Sound card line input switch allows switching of sound card audio input between interface box and another audio source.