receiver-decoder, in other words a complete digital satellite TV or radio receiver; "decoder" in this context refers not to decryption but to the decompression and conversion of MPEG video into displayable format. FTA is often used to refer to receivers and equipment which contain no decryption hardware, built with the intention of being able to receive unencrypted free-to-air broadcasts; more properly FTA refers to the unencrypted broadcasts themselves. A CAM or conditional-access module is defined by the DVB standard as an interface between a standardised DVB Common Interface receiver and one or more proprietary smartcards for signal decryption. It is not the smartcard itself. The standard format of this module follows PCMCIA specifications; some receivers bypass the requirement for a separate module by providing embedded CAM functionality in the receiver to communicate with specific proprietary smartcards such as Nagravision, Conax, Irdeto, Viaccess, Betacrypt. In the North American market, most "package receivers" sold by signal providers provide embedded CAM operation; terminology is therefore often misused to misidentify the smartcard as a CAM. JTAG is a standard test interface defined by the Joint Test Action Group and supported on many late-model digital receivers for factory test purposes. Operating using a six-wire interface and a personal computer, the JTAG interface was originally intended to provide a means to test and debug embedded hardware and software. In the satellite TV world, JTAG is most often used to obtain read-write access to nonvolatile memory within a digital receiver; initially programs such as Wall and JKeys were used to read box keys from receivers with embedded CAMs but JTAG has since proven its legitimate worth to satellite TV fans as a repair tool to fix receivers where the firmware (in flash memory) has been corrupted. The Sombrero de Patel is another device used to obtain direct memory access to a receiver without physically removing memory chips from the board to place them in sockets or read them with a specialized device programmer. The device consists of a standard PLCC integrated circuit socket which has been turned upside-down in order to be placed directly over a microprocessor already permanently soldered to a printed circuit board in a receiver; the socket makes electrical contact with all pins of the microprocessor and is interfaced to one or more microcontrollers which use direct memory access to pause the receiver's microprocessor and read or write directly to the memory. The term