Devices on the HP 3000 can transmit information in ASCII (American
Standard Code for Information Interchange) and/or binary code,
depending on the device.
For example, a line printer handles ASCII formatted data, while a disk
can transmit and store data in either format. You can use appropriate
optional parameters in HPFOPEN/FOPEN to specify the code (ASCII or
binary) in which a new file is to be recorded when it is written to a
device that supports both codes.
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 | NOTE: It is even possible to transmit and store data in EBCDIC, as long as the application program or subsystem (FCOPY, for example)
handles the decoding/encoding. EBCDIC is not handled automatically by MPE/iX. |
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With many devices, there is no restriction on the data actually transferred
to or from the file; you can write ASCII data to a binary file, or binary data
to an ASCII file. You can specify the type of code that you want, or accept the MPE/iX default for the device that you are using.
When the allocated record space is not filled by data, MPE/iX pads the unused
space with a fill character instead of good data. If you accessed this unused
portion of a record (for example, with the inhibit buffering option set to
NOBUF), you would find in the unallocated record space the fill character
specified at file creation.
The fill character may be different depending upon the mechanism you
used to create the file. If you create the file with FOPEN or
BUILD, MPE/iX pads an ASCII file with blanks and a binary file
with zeros. If you create the file with HPFOPEN, MPE/iX pads the
file with the fill character specified by the fill character
option (if not specified, the default fill character for files
created with HPFOPEN is blanks for ASCII files and NULL characters
for binary files).
Examples of ASCII files on the HP 3000 include program source files, general
text and document files, and MPE/iX stream files containing MPE/iX commands.
Examples of binary files include program files containing linked object code,
and application data files.
