Basic Communications; Several Computers' Print List Commands - Epson FX Series User Manual

Table
2-1.
If your listing is more than a page long (or if you didn't start the
listing at the top of a page), your printer may have printed right over
the perforation. Set DIP switch 2-3 to the on position, and the printer
will automatically skip over the perforation. We discuss this further in
Chapter 8.
Meanwhile, printing a program LISTing is a fundamental function
of the printer. Be sure you manage this before continuing (if you have
trouble, consult your computer's manual for help).

BASIC Communications

Part of the difficulty in controlling communications between com-
puter and printer is the lack of a completely standard coding scheme.
When your computer sends out a numeric code for the letter A, you
naturally want your printer to interpret that code as an A. Most man-
ufacturers of computers, printers, and software use the American
Standard Code for Information Interchange (ASCII, pronounced ask-
ee) to code such frequently used characters as the letters of the alpha-
bet, numerals, and keyboard symbols. Of the 256 ASCII numbers,
most are codes for specific characters; some are codes for such com-
puter or printer functions as sounding a beep or performing a carriage
return.
The ASCII standard does not yet allow for the advanced features in
today's computers and printers. Individual manufacturers therefore
adjust the codes to suit their own needs, which means that we are
often faced with compatibility problems between printers and com-
puters. (To compare your computer's version of the ASCII table with
the FX's version, see your computer manual and this manual's Appen-
dix A.) You can usually overcome the code inconsistencies by sending
control codes for advanced printer functions in care of a special ASCII
code that is called an ESCape code. The next five subsections discuss
these matters in more detail.
38

Several computers' print LIST commands