Help System (web edition)

A control line (with a '-' in the control column) in the print list
and having the form
  - include <text_file> 
specifies lines of a text file to be included as control lines.
The default directory for <text_file> is the current data directory
and secondarily, <Survo>\U\SYS on the system disk.
There is no default extension in the file name, but .DEV is recommended
for proper device drivers.

<text_file> usually contains define and shadow lines which describe
the features of the current printer for the PRINT program. Such a
text file can be considered a device driver, since all the information
about the printer has to be supplied by means of a series of - define,
- shadow, and other control lines.

The system file SURVO.APU defines the default device driver for
printing as print_dev=PS.DEV (for example) and then the lines
of the text file (device driver) PS.DEV are processed by the PRINT
operation as control lines before processing of lines in the print list.
Thus the task of the driver file is to teach the PRINT program all the
control words and codes of the current printer.
The default device driver is replaced by another by using a control line
of the form
  - include <text_file.DEV> 
as the first line (L1) in the print list of PRINT L1,L2.

The features described in device drivers are usually activated by
control lines of the form
 - [word1][word2][word3]
where strings in brackets are control words and macros defined
by - define lines in the print list or in include files (drivers).
For example,
 - [Times(12)][line_spacing(14)]
selects (according to PS.DEV) the 12 point Times-Roman font ([Times(12)])
and line spacing of 14 points ([line_spacing(14)]).

The user can make new device drivers for various printers by using any
existing Survo printer driver as a model or the user may modify and
enlarge the existing ones. For example, all the control words can be
translated to another language.

Please, note also that by referring to additional include files (for logos,
etc.) in the print list, the user can easily enter various enhancements
without the need to rewrite them completely.
  P = More information on PRINT