XON/XOFF flow control on LaserWriter+

keith gorlen nih-csl!keith at uunet.uu.net
Wed Feb 22 12:13:28 AEST 1989


I've succeeded in making the LaserWriter+ work from a Sun-3/50 running
SunOS 3.5 and Adobe TranScript 2.1.

The cable is simple:

	SUN workstation (3/50)                      LaserWriter

SUN workstation (3/50)                      LaserWriter

gnd (7)------<----------------------->-----(7)

RxD (3)------<----------\ /---------->-----(3) RxD
                         X
TxD (2)------>----------/ \----------<-----(2) TxD

/etc/printcap is also straightforward:

# local PostScript printer driven by TranScript software
lp|applejuice|lsmlaser|ps|postscript|PostScript:\
	:lp=/dev/ttya:sd=/usr/spool/lpd:\
	:lf=/usr/adm/lsmlaser-log:af=/usr/adm/lsmlaser.acct:\
	:br#9600:rw:fc#0000374:fs#0000003:xc#0:xs#0040040:\
	:mx#0:sf:sb:\
	:if=/usr/lib/ps/psif:\
	:of=/usr/lib/ps/psof:gf=/usr/lib/ps/psgf:\
	:nf=/usr/lib/ps/psnf:tf=/usr/lib/ps/pstf:\
	:rf=/usr/lib/ps/psrf:vf=/usr/lib/ps/psvf:\
	:cf=/usr/lib/ps/pscf:df=/usr/lib/ps/psdf:

Here is the tricky part: my LW+ was doing DTR flow control rather than
XON/XOFF.  To correct this send the following PostScript to the printer:

%!
serverdict begin 0 exitserver
statusdict begin 25 9600 0 setsccbatch

I found this in Appendix C of the LaserWriter IINT manual, and out of
desparation tried it on the LW+ with favorable results.

Thanks to all who responded to my question.
-- 
	Keith Gorlen			phone: (301) 496-5363
	Building 12A, Room 2017		uucp: uunet!nih-csl!keith
	National Institutes of Health	Internet: keith at alw.nih.gov
	Bethesda, MD 20892



More information about the Comp.sys.sun mailing list