The FT-950 supports data transmission in both USB and RTTY/PKT mode. The differences are shown in the table below.

Mode	Bandwidth	TX/RX
USB	~3kHz	Toggle Pin 3 of the RTTY/PKT connector (rear of radio). If you use CAT commands via HRD for switching TX/RX then audio I/O via the RTTY/PKT connector is not supported.
RTTY/PKT	~2kHz	Toggle Pin 3 of the RTTY/PKT connector (rear of radio) or use standard CAT commands via HRD.

If you want the best waterfall bandwidth then use USB and follow these steps:

• Select USB on the FT-950,
• In the DM780 Program Options select PTT,
• In the PTT page select via Serial (COM) port.

This option uses a second COM port to toggle a pin on the rear RTTY/PKT connector. The USInterface.com Navigator has two COM ports and supports this configuration.

If you only have one COM port then you cannot use it for both CAT control and toggling pin 3 on the RTTY/PKT connector.