Xerox 721 Message Manual - page 296

GLOSSARY

XEROX 4635 LASER PRINTING SYSTEM MESSAGE GUIDE

GLOSSARY-3

binary synchronous transmission

Data transmission in which synchronization of characters is

controlled by timing signals generated at the sending and

receiving stations.

bit

Abbreviation for binary digit, the smallest unit of information

recognized by a computer.  See also binary digit. 

bit map

Visual representation of graphic images in which a bit defines a

picture element (pixel); for example, if a bit is 1, the

corresponding pixel is printed.

bit mapped

Display image generated bit by bit for each point or dot.  A

software-driven scanner is used to create characters or graphics. 

blocking

Process of combining two or more records into a single block of

data which can then be moved, operated upon, or stored, as a

single unit by the computer.

block length

Number of characters or bytes contained in a block of data (the

block is treated as a unit within the computer).  Block length is

usually invariable within a system and may be specified in units

such as records, words, computer words, or characters. 

boot

To load the initial instructions of a program into computer

memory; these instructions then direct the loading of the rest of

the program.  Booting may require entry of a few commands at

the keyboard or the flip of a switch to begin the process. 

bps

bits per second.  In serial communication, the instantaneous bit

speed with which a device or channel transmits a character. 

BSC 

binary synchronous communication.  1.  Communication using

binary synchronous line discipline.  2.  Uniform procedure using

a standardized set of control characters and control character

sequences for synchronous transmission of binary-coded data

between stations.

buffer

Compartment of memory in which this data is stored during

transfer from one device to another.  This is useful for

accumulating data into blocks before storage or processing and

for adjusting differences of speed between devices, or between a

device and a communicating facility.

Bypass Transport 

Optional module that moves paper from the last stacker bin to a

finishing device. 

byte

Fixed number of bits (in data processing, usually 8) operated

upon as a unit.  A byte may represent a character, a machine

instruction, or some other logical unit of information.