[comp.lang.postscript] Summary of responses about low-end Postscript printers

oliver@fire.berkeley.edu (05/10/91)

About a week ago, I posted a question asking about low-end Postscript
printers.  I was particularly curious about the QMS PS410, the TI
MicroLaser, and the Printer Works JetScript/Canon engine combination.

There certainly seem to be a lot of cheerful laser printer owners out
there :-).  The responses about the QMS spanned the entire range from
"it works fine, I recommend it" to "since I bought a 410, I have become
wise, wealthy, and even my dog likes me".  One person reported that the
machine had been damaged en route, but was fixed by QMS immediately.
All of the four people who had or had used TI printers liked and recommended
them as well.  The only person with anything bad to say said that he had
had a bad experience with the JetScript controller.

So, I'm still not quite sure whether to get the TI or the QMS.  I'm leaning
towards the former because it is small and a bit cheaper, but I have been
left with a very good impression of the 410 and I may go ahead and spring
for one if I can find a good deal.  It sounds like I should be in pretty
good shape either way.  I'd like to thank everyone who responded, and I 
hope this summary is useful to someone else.

The replies came from:

bryan@cs.utexas.edu (Bryan Bayerdorffer @ Wit's End)
tneff@bfmny0.BFM.COM (Tom Neff)
Steve Owens <owens@cse.ogi.edu>
peb@pine.pine.dk (Per Baekgaard)
unmvax!gatech!dcatla!dudkl@ucbvax.Berkeley.EDU  (Danny Llewallyn)
adpplz!dtb@apple.com (Tom Beach)
gatech!motatl!mcdchg!gargoyle!chinet.chi.il.us!pdg@ucbvax.Berkeley.EDU (Paul Guthrie)
lee@shell.com (Bill Lee)
Joseph_Keenan@NeXT.COM


Thanks, everyone.
Cheers,
- Oliver

woody@chinacat.Unicom.COM (Woody Baker @ Eagle Signal) (05/13/91)

In article <13530@pasteur.Berkeley.EDU>, oliver@fire.berkeley.edu writes:
> About a week ago, I posted a question asking about low-end Postscript
> printers.  I was particularly curious about the QMS PS410, the TI
> MicroLaser, and the Printer Works JetScript/Canon engine combination.
> 
> 
> So, I'm still not quite sure whether to get the TI or the QMS.  I'm leaning
> towards the former because it is small and a bit cheaper, but I have been
> left with a very good impression of the 410 and I may go ahead and spring


I think that I'd ask whether the TI is a black or white writer.  The 410, I
belive is a black writer.  The diffrence in output is subtle, but important.

A blackwriter generates black dots everywhere the laser hits the drum.  The
normal unexposed drum will generate a white page.  The whitewriter on the
other hand REMOVES toner everywhere the beam touches the drum.  Now, since
lasers are essentialy round rather than ssquare pixels, you have to somehow
fint a round dot in a square (1/300th inch) spot.  There are 3 ways to do this.
1.  Make the dot stay within the bounds of the square pixel.  Draw a box, with
a dot in it that just touches the inside edges of the box.  2. expand the
dot a bit, so that it stays INSIDE the box at the corners, but bulges outside
of the box at the 4 edges.  3.  Encompass the entire box with the dot.
Most blackwriters use number 2 and adjust the toner, charge, and laser such that
the small unexposed diamonds between the dots will fill in anyway.  (draw 4
circles so the edges all touch, and you will see the diamond that I am talking
about here.  This will not work with a white writer.  You wind up with little
thin black lines etc over your page.  For a white writer, you have to use
option number 3.  This has the effect that a single row of pixels will have
nibbles taken out of the side.  You can get some graph paper and prove this
quite easily.  The bottom line, is that a whitewriter tends to have intense
solid blacks, but often times single pixels won't image properly.   3, 4 or
5 point type for example, TImes-Roman wiil have open spaces at the top and 
bottom of things like o's and e's.  In general, for find detail you want
one of the blackwriters.  If you are going to be doing something like creating
silkscreen masks, where the screen is say 150 mesh, then the loss of fine
resolution won't matter, because you need the solid blacks more than
the resolution.

Cheers
Woody

geof@aurora.com (Geoffrey H. Cooper) (05/16/91)

In article <2000@chinacat.Unicom.COM> woody@chinacat.Unicom.COM (Woody Baker @ Eagle Signal) writes:
>In article <13530@pasteur.Berkeley.EDU>, oliver@fire.berkeley.edu writes:

>> So, I'm still not quite sure whether to get the TI or the QMS.  I'm leaning
>> towards the former because it is small and a bit cheaper, but I have been

>I think that I'd ask whether the TI is a black or white writer.  The 410, I
>belive is a black writer.  The diffrence in output is subtle, but important.

The 410 is based on the Canon LBP-LX, which is a write-black machine.
The quality of output on this marking engine is tied for the best I've
ever seen -- with the Canon LBP-SX that is used in the LJ III, QMS
810, LaserWriter NT&NTX...  Individual pixels stand out nicely and a
solid black is very black.

The 410 itself is both more expensive and better than competition
because it has a 32-bit processor (68020);  this allows it to improve
response time (time from hitting the RETURN key to getting output)
over 16-bit processor models.

- Geof
-- 
geof@aurora.com / aurora!geof@decwrl.dec.com / geof%aurora.com@decwrl.dec.com

hebert@wolves.uucp (Jim Hebert) (05/16/91)

Probably a dumb question, but do I care if the postscript printer I'm
interested in has a Cannon -CX vs -SX vs <mumble>X engine?  If so,
how do they differ?

Thanks in advance,

Jim

woody@chinacat.unicom.com (Woody Baker @ Eagle Signal) (05/17/91)

It makes a very big diffrence if you need high resolution or
deep blacks.  For example the CX engine always has washed out blacks
with gray streaking (the original).  This was because the toner, charge 
balance and spot size were not properly matched.  Using a 3rd party
reload toner helps this out.  The SX has a much better matched toner, charge
and spot size.
Cheers
Woody