Also called speed dialing. By concentrating the control instruction sequences in a common subroutine, the programmer's task of producing a program is simpified. It provides a logical, rather than physical, set of references. Communications access methods have always required large amounts of main memory. In a medium size system, supporting a few dozen terminals of dissimilar types, 80K to 100K bytes of storage is not an unusual requirement.
Precision refers to the degree of preciseness of a measurement.
Digital signals are modulated as sound waves and data rates are typically limited to about 300 bps, some up to 1.2K bps. The percentage of time during the busiest traffic hour that a signal is present in a channel in either direction. There are many characteristics, logical and physical, of a computer and communications system that cannot be specified with high accuracy before the actual installation is made. Adaptive refers to a capability for accommodating a wide variation in one or more system characteristics and still performing the intended function. The word implies that the adjustment is made automatically.