LP(4)

NAME
lp - line printer

SYNOPSIS
/sys/conf/SYSTEM:
	NLP	lp_printers	# Line Printer
	LP_MAXCOL	132	# Maximum number of columns on line printers
/etc/dtab:
	#Name	Unit#	Addr	Vector	Br	Handler(s)		# Comments
	lp	?	177514	200	4	lpintr		# lp-11 line printer
major device number(s):
	raw: 5
minor device encoding:
	bit 01 specifies 64-character set (instead of 96-character set)
	bits 06 are reserved
	bits 0370 specify line printer unit: <lp_unit> * 8

DESCRIPTION
Lp provides the interface to any of the standard DEC line printers on an LP-11 parallel interface. When it is opened or closed, a suitable number of page ejects is generated. Bytes written are printed.

The unit number of the printer is specified by the minor device after removing the low 3 bits, which act as per-device parameters. Currently only the lowest of the low three bits is interpreted: if it is set, the device is treated as having a 64-character set, rather than a full 96-character set. In the resulting half-ASCII mode, lower case letters are turned into upper case and certain characters are escaped according to the following table:

{   -

}   -

`   -

|

~

The driver correctly interprets carriage returns, backspaces, tabs, and form feeds. Lines longer than the maximum page width are truncated. The page width is specified via the LP_MAXCOL definition, set to 132 in the GENERIC distribution.

FILES
/dev/lp
/dev/MAKEDEV    script to create special files
/dev/MAKEDEV.local    script to localize special files

SEE ALSO
lpr(1), dtab(5), autoconfig(8)

DIAGNOSTICS
None.

BUGS
Although the driver supports multiple printers this has never been tried.