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From: tjr@cbnewsc.ATT.COM (thomas.j.roberts)
Newsgroups: comp.sys.ibm.pc
Subject: Re: HP Desk Jet - Opinions
Message-ID: <3080@cbnewsc.ATT.COM>
Date: 11 Sep 89 16:00:27 GMT
References: <12416@athertn.Atherton.COM>
Distribution: comp
Organization: AT&T Bell Laboratories
Lines: 33

BEWARE: the DeskJet has problems with page-length, due to its inability
to print on the last 1/2 inch of a page.
If you simply cat (or type) a file to it (one that is merely a series
of lines, no Form-Feeds). It will either:

	a) work fine, skipping the first and last 3 lines per page
	   (Perf-skip mode on)
	b) print 63 lines on Page 1, 3 lines on Page 2, 63 lines on Page 3,
	   3 lines on page 4, etc... (Perf-skip mode off)

While (a) might work for this case, if you then use it with a program
that expects 66 lines per page (such as pr, troff, ...), the pages will
quickly get out of sync. (b) is the ugliest thing I have ever seen.

Why HP decided to print only 3 lines on every other page is beyond my
comprehension - it's a lousy way to try to preserve page boundaries,
especially since such programs usually don't care about page boundaries.

I have written a UNIX/MS-DOS filter to do the following:
	On every page, preceed line 64 (if it exists) with a form-feed.
	If lines 64,65,66 exist and are blank, delete them.
	If lines 64,65,66 do not exist, they must have been deleted by
		a form-feed on input, so there is no problem.
	If there is a form-feed on line 1 (top of page), delete it.

This algorithm allows me to leave the DeskJet in no-perforation-skip
mode, and use any program without worrying about whether it outputs
form-feeds or 66 blank lines to eject a page. Someday I will turn it
into a device driver rather than a filter; for now, appropriate aliasing
in ksh (UNIX) and CED (MS-DOS) solves most of my problems.

Tom Roberts
att!ihnet!tjr