Xerox Paris, a document system Support & Software User Guide

The purpose of a Translation Table in the PARIS Designer is to translate individual
characters in the printstream character set to another character set. Why is this
necessary? To begin with, let’s consider the data in the input printstream.

An input printstream consists of a series of bytes, each representing either a
printable character or line/page terminator. Of the 256 possible byte combinations,
the lowest 16 are normally reserved for special characters such as line feeds and
form feeds while the rest correspond to printable characters.

These byte combinations are relevant to the way computers communicate as the
computers must agree on which byte value corresponds to which character. This is
done according to a recognized encoding system and is best explained by revising the
way a computer organizes data.

Computers store data as 1s and 0s, or binary digits called bits.

A bit has two possible states, ‘on’ or ‘off’ and in the binary numbering system (base
2) and in written text, the on-bit is a 1 and the off-bit is a 0.

According to a recognized  encoding system, a series of 

bits are combined to

represent a character. This combination of bits is called a byte.

A byte is made up of eight binary bits, therefore each byte (eight bits) could have
one of 256 (2

8

) possible configurations of ‘on’ and ‘off’ states. For example, in 

the

ASCII encoding system the bit configurations of 01000001 and 01000010 represent
the characters A and B .

Unfortunately there is no absolute standard of encoding systems, however two
general standards do exist. Of these, ASCII (American Standard Code for
Information Interchange) has generally emerged as the standard by which PC and
network systems communicate. The other standard called EBCDIC (

Extended

Binary-Code Decimal Interchange Code), is used primarily by mainframe
computers.