Abstract: Disclosed is apparatus for processing an encrypted data stream within a computer system adapted to receive the encrypted data stream from a data storage device. A data output device is coupled to a computer system and has a plurality of data output areas. An encrypted data stream is transferred from a data storage device to the data output device, the encrypted data stream being for output to one of the plurality of data output areas. The encrypted data stream is received and decrypted to produce a clear data stream for output to one of the plurality of data output areas. A decryption means receives a decryption key from the computer system, the decryption key relating only to the encrypted stream associated with the one of the plurality of data output areas.

Abstract: Display apparatus comprises a connection for releasably connecting a display device (130;130') to the display apparatus. A data input (MON.sub.-- ID) receives first data from a first releasable connection (ST) to the display device (130;130') and for receiving second data from a second releasable connection (ID) to the display device (130;130'). Switch (320) selectively connects the data input (MON.sub.-- ID) to either of the first releasable connection (ST) and the second releasable connection (ID). Display processor logic (310) is connected to the switch (320) for generating one or more video signals to generate an image on the display device (130,130') as a function of the data directed to the data input (MON.sub.-- ID) from the display device (130;130') by the switch (320).