27
line feed -the name of the code
UJ’) -its abbreviation
ASCII 10 -its decimal value
ASCII &HOA -its hexadecimal value (the &H signifies
CHR$(lO)
CTRL- J
hex)
-the way it’s used in BASIC
-the way you send it from a keyboard
Of course, most of the time we don’t need to bother with
these. Our computers are smart enough to know that when we
press the “A” key we want to print the letter “A” - they take
care of all the intermediate steps.
Appendix B is a table that shows the various names for each
code so you can convert back and forth. The microcomputer
world is not very consistent in describing ASCII codes, so it’s
important that you have a basic knowledge of them.
n The escape codes
Back when the ASCII system was set up, computer equip-
ment was relatively simple and thirty-three control codes were
considered sufficient at the time. The American Standards
people realized that, eventually, more control codes would be
needed so they included the escape (ESC) code to allow almost
any number of additional codes to be defined when they became
necessary.
ESC allows us to “escape” from the ordinary set of control
codes so we can specify additional functions and other informa-
tion needed for a printer function. In this manual, we’ll write the
ESC code inside broken brackets, like this - (ESC).
(ESC) - ,decimal 27 - is always followed by at least one
other number; it is never used alone. The whole series of related
numbers is called an escape sequence.
W A note on command syntax
Because the readers of this manual will be running such a
wide variety of applications on so many different computers, we
just can’t show the exact way of sending codes to the printer for
each one of them. Instead, as we introduce you to each new com-
mand, we will show the commands as in this example:
(ESC) “W” 1