Epson LQ-2550 User Manual - Page 134

The actual character definition starts in line 20. The two at signs (@) in line 30 represent nl and FG!, the range of characters being defined (in this case, a range of one). Line 40 contains do, dl, and d2. The information about the actual character design (which is contained in the data statements at the end of the program) is sent to the printer in the loop between lines 50 and 70. Note: When defining Letter Quality or proportional characters in BASIC, put a WIDTH statement in your program to prevent carriage return and line feed codes from interfering with your definitions. Printing user-defined characters The example program above defines an arrow and places it in the RAM location for ASCII code 64 (replacing the @ sign). When you run the program, it prints a three-line sample of your work. The first and third lines (printed by lines 80 and 120 of the program) print the normal @ sign: the second line (line 100) prints the arrow that you defined. Run the program to see the printout below: @@@@rO TTTTT @@@@@ As you can see, both sets of characters (the original ROM characters that the printer normally uses and the user-defined character set) remain in the printer available for your use. The command to switch between the two sets is used in line 90 and 110: ESC % n If n is 0, the normal ROM character set is selected (this is the default). If n is 1, the user-defined character set is selected. If you select the userdefined character set before you have defined any characters, the command is ignored and the ROM characters remain in use. Using Software and Graphics 4-29