Single-Pass Overstrikes; Escape Sequences; Form Length Escape Sequences - Texas Instruments 880 User Manual

Table 5-2. Control Character Operations (concluded)
Decimal Control
Char
Hex
Code Code Description and Operation
DC3 13 19 Device Control 3. Cnfg. code 83 ON: Transmitted on serial interface to indicate
BUSY.
DC4 14 20 Device Control 4. Tab to column of decimal number of next byte.
EM 19 25 End of Message. Next character printed is from G2 character set.
ESC 1B 27 Escape. Cnfg. code 81 OFF: Characters that follow are printed. Code 81 ON: Escape
sequence commands are executed.
GS 10 29 Group Select. Next character printed is from G3 character set.
5.2 SINGLE-PASS OVERSTRIKES
The Model 880 Printer does single-pass over-
strikes to support single-pass underlines in draft
and enhanced modes. The sequence, character-
backspace-character, is recognized as a single-
pass overstrike. The single-pass character dot
pattern is formed by merging the dot patterns of
the two characters.
5.3 ESCAPE SEQUENCES
The host can control printer operation through
escape sequences. In the tables that follow, some
escape sequences are given in two formats in
which the line number, column number, or form
length is represented as Nor n.
The number
N
is entered as an ordinary decimal
number. For example, if N represents the number
25 in an escape sequence, 25 is entered as a 2 and
a 5. The ASCII characters 2 and 5 are sent to the
printer.
The number
n
represents the decimal code for
character
n
in Table 5-1. For example, if
n
repre-
sents the number 25 in an escape sequence, the
code for character 25 (EM) in the ASCII table is
entered. The ASCII character EM is sent to the
printer.
In the following escape sequence tables, the deci-
mal codes for the escape sequence characters are
given as examples.
NOTE
Do not enter spaces between the
ASCII characters in the escape
sequence commands. The spaces
shown between the characters in these
tables are for readability.
5.3.1 Form Length Escape Sequences
The form length is expressed as the number of
lines in a form. The form length is set according to
the currently enabled vertical pitch. Once the form
length has been set, the actual size of the form
remains the same until the form length is set dif-
ferently, even though the vertical pitch may
change. See Table 5-3.
5-3