Figure 12-1.—Samples of different fonts.
An escape control code is the ASCII escape code
(27) followed by one or more additional characters. For
example, a dot matrix printer may use ESCAPE C to
start underlining text and ESCAPE D to stop
underlining. Another example of an escape control
code could be ESCAPE (s1S) to select italics as the
style of print. The decimal representation of this string
is 027, 040, 115, 049, 083.
Controlling the medium- and high-speed printers
used with mainframe computers is accomplished with
external function messages from the computer. These
printers use ASCII codes to determine the characters to
be printed.
LINE CHARACTERISTICS
Line characteristics refer to the method of character
spacing, the size of the characters, the number of
characters printed per line, and the number of lines per
inch.
Character Spacing
Depending on the type of printer being used,
character spacing can be freed or proportional. Fixed
spacing means each character, upper and lower case,
requires the same amount of space on the line. With
proportional spacing, narrower letters use less space
than wider letters. For example, a lowercase i requires
less space than an upper case W. With proportional
spacing, the number of characters per inch is an
approximation.
With fixed spacing, the number is
always the same.
Character Size
Character size can be affected by many factors,
depending on the type of printer being used. Drum
printer character size is freed and difficult to change.
Most dot matrix and laser printers can print a wide
variety of character sizes and fonts. Font refers to the
style of the typeface, such as Courier, Times New
Roman, or Ariel, combined with the size of print and
the stroke weight (for example, bold). Figure 12-1
illustrates several common fonts.
Character size is also selectable on many printers.
Character size is expressed in terms of pitch (characters
per inch) or point size. Point refers to a printer's
measure of print height. One point is equal to 1/72 inch.
All the fonts illustrated in figure 12-1 are 12-point fonts.
Note how the typeface affects the character spacing.
Figure 12-2 illustrates the same typeface printed in
several different point sizes.
ORIENTATION
Orientation refers to how the characters are printed
on the page. There are two modes of orientation:
portrait and landscape. When portrait mode is
selected, the data is printed across the width of the page.
Figure 12-2.—Samples of different point sizes of the same typeface.
12-4
