From: dnichols@ceilidh.beartrack.com (Don Nichols (DoN.))
Newsgroups: comp.sys.3b1,comp.periphs.printers
Subject: Re: Transparent communications thru parallel port/HP LJIIP+
Date: 15 Aug 92 00:16:14 GMT
Organization: D and D Data, Vienna Virginia

In article <1992Aug13.142629.8120@bwdls61.bnr.ca> clewis@ferret.ocunix.on.ca (Chris Lewis) writes:
>I just got a HP LJ IIP plus (so now I can test psroff
>before issuing patches ;-) which I've connected to my

	[ ... ]

>                          Or, does the lp driver support
>other minor device numbers for suppressed transforms?

	Sure does.  Look for /dev/rawlp.  It is a raw as you could ever want.

>I'd rather not have to binary zap the driver...

	No need.

	[ ... ]

>cheap in terms of communications time.  Besides, I think
>my one remaining free serial port got fried by a line transient.
>

	If so, it is most likely to be the line drivers and receivers that
got zapped.  I don't have time at the moment to dig into the TRM to find
which chips and where, but they are probably 1488 and 1489 chips (or their
TI-numbered equivalents, which I *THINK* are something like 75188 and 75189.
                                                             ^         ^
NOTE those "5"s.  They are *NOT* a typo, it is a different family of chips
to get the voltages needed.

	If you don't have the TRM, drop me e-mail, and I'll try to look up
what the chips actually are, and where they are located.  Be sure to replace
the chips with *good* sockets, so replacement will be easier if another
transient takes them out again. (It'll also minimize heat damage to the
board, limiting to only one desoldering/resoldering.  Don't even *think* of
trying to save the chips.  Just clip them free - at the chip body - and
unsolder the pins individually.  The board is worth *far* more than any chip
on it.

	[ ... ]

>My second question: I'll probably be wanting to upgrade the
>LJIIP+ in the future.  More memory, and/or PostScript cartridge.
>What alternatives to HP are there?  Particularly in memory.

	Well, I use the PacificPage PostScript cartridge, and the Pacific
1-2-4 ram card, which is now fully populted with 4MB of ram.  (This is in a
II, not a IIP, and the documentation implies a different cartridge and ram
card are needed by the IIP.  They make them as well.)  I am quite pleased
with the behavior of the combination on the II, and we use them at work
also.  The results are not as quick as they are on one of our dedicated
PostScript printers, but I can't tell the difference visually.  (Well,
really I can, because one of the dedicated printers is getting old enough so
that it doesn't produce nice, crisp, images like the HP does. :-)

BTW	Groff does produce nice curved, and non-parallel lines using ditroff
commands and the PacificPage PostScript cartridge.  I haven't mastered that
set of commands, but an RFC with some diagrams done that way looked good.

	Good Luck
		DoN.
-- 
Donald Nichols (DoN.)     | Voice (Days): (703) 704-2280 (Eves): (703) 938-4564
D&D Data                  |  Email: <dnichols@ceilidh.beartrack.com>
I said it - no one else   |         <nichols@nvl.army.mil>
	--- Black Holes are where God is dividing by zero ---
Newsgroups: comp.sys.3b1