From: clewis@ferret.ocunix.on.ca (Chris Lewis)
Newsgroups: comp.sys.3b1,comp.periphs.printers
Subject: Re: Transparent communications thru parallel port/HP LJIIP+
Date: 17 Aug 92 04:05:56 GMT
Followup-To: comp.sys.3b1
Organization: Elegant Communications Inc., Ottawa, Canada

In article <1992Aug15.001614.3086@ceilidh.beartrack.com> dnichols@ceilidh.beartrack.com (Don Nichols (DoN.)) writes:
>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.

Boy do I feel silly.  About a half hour after my posting, I did a
ls -l "/dev/*lp*"....  What's really annoying is how badly Convergent
broke lp's accept and lpadmin utilities.  (they won't print errors,
lpadmin had to be invoked as root, accept as lp...)

>>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.

Yes, I'm aware of the parts.  We do have a copy of the TRM (in another city),
but if I ever get around to diagnosing the problem (if it wasn't just a stuck
device driver), I can trace the leads from the connectors.  This is on
the combo board, not the motherboard, so it's easy.

[During a thunderstorm, I shut down the 3b1, disconnected it and the modem
from power and the phone lines.  I forgot to disconnect the terminal and
RS232 line.  The terminal still works, but the port seemed dead, so I moved
the terminal to the other port on the combo.  I have a solder sucker
somewhere, so fixing it wouldn't be hard.]

Thanks for the references to Pacific Page for memory.

>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.

Psroff does nice lines on PostScript too.  But that's no fun.  I want to
complete psroff's LJ support (drawing commands other than vertical and
horizontal lines aren't supported), so that you can do full troff with
Laserjets and Laserjet IIs (PCL4).  Psroff can do full troff on Laserjet IIIs
(PCL5) by switching to HPGL for the drawing commands.

Groff doesn't have a PCL (HP Laserjet) driver as yet.  Combined with psroff,
groff can print to HP Laserjets.  And all PBM-supported devices.  Including
G3 fax, 3b1 screens, 24 pin matrix printers etc.  Without having to resort
to GhostScript.  The results on LJIII's via PCL5 looks particularly good.
Better, in fact, than PostScript on most printers (IMHO).

Actually, rather than PostScript, I'm half tempted to upgrade the IIp+
to PCL5 instead.  For my purposes, PCL5 is as good as PostScript, and it's
somewhat cheaper.
-- 
Chris Lewis; clewis@ferret.ocunix.on.ca; Phone: Canada 613 832-0541
Psroff 3.0 info: psroff-request@ferret.ocunix.on.ca
Ferret list: ferret-request@ferret.ocunix.on.ca
Newsgroups: comp.sys.3b1