Nlynx ETU400 - Manual (Page 53)

ETU400 User Guide 011603 4-7
About Translating Files
You must usually translate data when you transfer it between a
microcomputer and the host. That's because the host and the microcomputer
have very different data storage methods. The remainder of this chapter
explains the differences between host and micro data, and the two types
of translations ETU performs to overcome those differences.
How Data is Stored
The way data is stored on the AS/400 is considerably different from the
way it is stored on the micro.
On the AS/400:
• Files are stored in fixed-length records;
• Field definitions are usually maintained external to the file;
• Data is stored in an EBCDIC character set.
On the PC:
• Files are stored in fixed or variable-length records;
• Multiple field definition formats exist;
Internal (fields defined as part of the data),
External (fields defined outside of the file),
NO field definitions (character data only);
• Data is stored in an ASCII character set.
To accommodate these differences ETU performs two types of translations.
It translates data between ASCII and EBCDIC, and it also reformats the
data into one of the various microcomputer file formats. To perform the
ASCII-to-EBCDIC translation, ETU uses translation tables, which are
explained on the following page. The different microcomputer file formats
are explained on page 4-11.