USB Interface
To operate the DR-9400 modem like the old DR-7X00 modems over a virtual COM port via USB, you
need to install a new SCS-USB driver.

Note: For Windows 11 users this new driver also works with 7400/7800 series modems
First, completely delete or uninstall the previous SCS-USB driver. You can do this in the Device
Manager by selecting "Uninstall device" or in the Apps & Features section of Windows by
searching for SCS and removing the driver.
Then, proceed with installing the new driver:
Download the entire ZIP archive of the driver from the following URL:
Please disconnect all modems from the computer before installing the driver!
Locally extract the ZIP archive. In the main directory of the archive, you will find the executable
file dpinst64.exe.
Run dpinst64.exe as an Administrator and follow the instructions.
This installs the driver. There is only a 64-bit version available, as Microsoft no longer supports
the 32-bit version. All old SCS modems are supported by this driver, which also resolves issues
with the previous driver on Windows 11.
After connecting the DR-9400, a virtual COM port will be created with the name similar to "SCS PXdragon 9400 (COM6)"
This virtual COM port can be used as usual in terminal software and other modem-related
software. The DR-9400 behaves essentially like a DR-7400, so it should be compatible with
all standard applications.