such as Rockline, Hollywood Live, several live concerts, and some Westwood One content. These uplinks allowed producers of program to send pre-recorded or live material to an uplink in their region instead of having to send by mail or haul it by expensive telco lines to NPR's MOTC (Main Origination Technical Center, the analog PRSS predecessor to NPR's NOC) Washington uplink. Some of the very first stations to have their own uplink facilities to PRSS were KUT in Austin, Texas, and Minnesota Public Radio, both in 1980, and KUSC, Los Angeles, who provided the bulk of the commercial radio revenue uplinks, at about the same time. Later versions Satellite Operations Support System (SOSS) Around 1994, the 1st generation analog PRSS system was upgraded to a new system using digital audio feeds instead of analog, and automated receiver selection and tuning of feeds (using a dedicated PC). This system was known as the SOSS, or Satellite Operations Support System. Analog feeds were discontinued, and instead uplinked digitally (but still in SCPC fashion and on 2 satellite transponders) using Musicam encoding, and received using ComStream ABR-700 digital audio satellite demodulators, which tapped off the 70 MHz IF bus of a Satellite System Corporation Model 4421 downconverter, which was in essence the main satellite receiver for the system, taking in the L-band input from the dish's LNB. There were seven ABR-700 demodulators (or "demods") used: six for audio program feeds (each demod was referred to as "NPR A" through "NPR F"), and a seventh for reception of data only (called the Downlink Service Channel, or DSC). The DSC demod was interfaced to the SOSS PC, which ran custom control software running under OS/2 Warp. Using SCPC frequency & satellite transponder data for program feeds received from the DSC demod (which was tuned to a fixed transponder and SCPC frequency), the software would automatically tune any one of the six audio demods to whatever program feeds the station would want to receive (the 1st generation analog PRSS receivers had to be tuned manually for each feed). DACS messaging functions were also integrated into the SOSS PC using its software and the DSC demod. The six audio demods were controlled by the SOSS PC via several RS-485 serial connections from a board installed in the PC called the ARTIC board ("A Real-Time Interface Co-Processor"), with each demod respectively equipped with a RS-485 serial control interface.