ABSTRACT
Timecode is a digital signal. It carries information as a sequence of zeros (0s) and ones (1s), called 'digits'. These digits may represent quantities such as time or film footage, or they may carry 'command' and 'control' information. The assembly of these digits is called 'data'. Just as letters, numbers and characters have to be assembled into recognizable forms (languages) in order to be meaningful, so data must be arranged into recognizable forms in order to carry information. The arrangement of data is referred to as 'protocol'. Protocols define such matters as the number of digits used to form individual data words, the order in which data are presented within the words and the way in which the words are grouped together to carry information. There are a number of protocols used in the carrying of timecode data, depending on the application concerned. This need not be a problem because, as with languages, it is possible to translate from one protocol to another. This chapter will examine the various forms in which information may be carried within digital systems concerned with timecode, and starts by examining the nature of number systems.
