As part of the PRINT statement, Tab() functions provide a compact interface to a wide variety of capabilities, ranging from basic green screen terminal commands to exotic workstation functions. The two general clases of Print Tab Functions are:
• Terminal Functions, by which we mean functions that are used with traditional or "dumb" terminals. These were originally known as "TCRT" calls, although the origin of that acronym is unknown.
• ATE Functions which are used only with "smart" terminals, also known as "clients" or "workstations." In A-Shell environments, the usual smart client is a PC running A-Shell's terminal emulator software ATE.