HP 3000 Manuals HP 3000 Manuals
Mapping at a Glance
The situation for most western European customers is as follows:
* The HP Vectra and IBM PCs operate in IBM8. Access PC uses ROMAN-8
to communicate with Access Server on the host HP 3000. We can
therefore consider the PC a ROMAN-8 machine.
The following figure summarizes the situation:
Click here to view figure.
Figure D-1. ROMAN-8 and ISO-7 Mapping at a Glance
The arrows and the words Best Fit and Exact in the figure show that the
direction of the communication determines how accurately the characters
are mapped:
* Mapping ISO-7 to ROMAN-8 usually gives an exact mapping since all
characters in the ISO-7 character set also exist in ROMAN-8. The
exception is discussed below.
* Mapping ROMAN-8 to ISO-7 gives an exact mapping for characters
whose decimal representation is 127 or less and for characters
which map back to the twelve special characters shown in Figure D-
2. For other characters whose decimal representation exceeds 127,
the mapping is only approximate.
Data traveling "round trip," such as PC data uploaded to a saved table on
the host HP 3000 and later downloaded to the PC, may lose information.
This occurs because at least one part of a round trip involves a "Best
Fit" mapping. (Round trips are discussed in more detail later in this
appendix.)