CHAPTER 6
SPECIALFEATURESOF THEPRINTERSubjects covered in Chapter 6 include -
l Printer’s bell
@ Master reset
l Uni-directional printing
l International character sets
l Printing BIG characters
l The optional sheet feeder
l Macro instruction
l Reading a hex dump
In the previous chapters we have learned about several groups
of control codes. In this chapter we will look at more control
codes. These codes don’t fit neatly into any of the groupings
that we have looked at so far, but they add a lot of useful
features to your printer.
L Now hear this
You may have heard the printer’s bell if you have ever run
out of paper. And you may have wondered why it’s called a
bell when it beeps instead of ringing! It’s a long story that goes
back to the early days of computers, when teletype machines
were used for computer terminals. These mechanical marvels
were equipped with a bell that could be heard for blocks. This
bell was used to signal the operator that something needed
attention. The code that the computer sent to the teletype
machine to ring the b&l1 was reasonably enough, called a bell
code. The name bell code is still with us, even if the bell has
changed to a beeper, and a lot of people still call the beeper
a bell, even if it doesn’t sound like one.
The code to sound the “bell” is CHR$(7), which is ASCII
code 7 or <: BEL > . Any time your printer receives this code