Character Repertoires And Character Sets - Digital Equipment LB12 Field Support Manual

2.2.3

Character repertoires and character sets

2-28
Figure 2-30 Character formation at 300cpi print speed
A "character repertoire" is a defined collection of characters with no coded representation.
A collection of characters defined together with its coded representation is called a "coded
character set", or simply, a "character set". Note that a character set does not define the
graphical representation of the characters, i.e. the type-face to be used.
The total character repertoire that can be used by the printer is divided into one basic and
several additional repertoires.
The basic repertoire consists of 190 characters, including 178 characters that form a subset
of the basic Teletex repertoire defined in CCITT recommendation T.61. The basic repertoire
is almost identical to that of EBCDIC.
The basic repertoire is represented by several pairs of 8-bit coded character sets. Each pair
contains a primary set of 94 characters and a supplementary set of 96 characters. Each
pair constitutes a national version and is defined in such a way that its primary set is
identical to the corresponding national version of the 7-bit code.
An additional repertoire consists of up to 192 characters and is represented by one or two
8-bit coded character sets. Each of these sets is unique, i.e. there are no national versions.
The EPROM part of the printer memory contains various character sets. Other character
sets, containing for example logotypes and graphics characters, can be added by
downloading them from the workstation controller into the printer's RAM area. This means
that the number of available graphic characters is theoretically unlimited.
LB12/LB15 Field Support Manual 9710