The GM950 RSS is widely available on radio enthusiast forums, Ham radio websites, and eBay (sold on floppy disks or CDs). Common sources include:
The GM950 requires a true RS-232 voltage level (typically -12V to +12V). USB-to-Serial adapters using the Prolific PL2303 or FTDI chipset can work, but you must disable "advanced power management" on the COM port in Windows and ensure the RIB box is powered (usually by the radio's +12V on pin 10 or an external battery). motorola gm950 programming software