Xerox 4215 Reference Manual page 215

XEROX MRP FAMILY COAX COMMAND REFERENCE
Table D-4. Field attribute (FA) character definitions
Bit Value Description
0,1 11 Field attribute identifier
2,3,4,5 XX11 Nonprint field
XX10 Print field
XX01 Print field
XX00 Print field
6,7 00 Reserved
If the first character in a print order is not an attribute character,
the attribute of the first field is determined as follows:
The print data is searched backwards for a field attribute from
•
MSA + ML-1 to MSA ignoring EM control codes. The first
FA found is then treated as if it had occurred at the MSA.
If no FA is in the data, printing defaults to the normal
•
unprotected attribute X'C0' (print field).
Some of the print data requires special attributes, such as
highlighting, color, and the APL character set. For data requiring
such specification, the host system places the data byte in the
base buffer and the appropriate place in the extended attribute
buffer (EAB).
If bit 4 in the PCIA order byte X'0017' is on, the printer uses the
attribute data contained in the EAB to determine the appearance
of the printed output.
Usually the extended field attribute (EFA) is at the beginning of
the EAB. If it is not there, a similar search procedure is executed
to find the first FA.
If the EAB modifies an FA byte in the base buffer, it is an EFA.
See table D-5.
Table D-5. Extended field attribute (EFA)
Bit Value Description
0—1 00 Normal mode
01 Blink character (ignored)
10 Reverse video character (ignored)
11 Underline character (including spaces and
nulls)
2—4 xxx Black
5—7 000 Base DSC character set
001 APL DSC character set
COAX COMMUNICATIONS BUFFER
D-9