[fa.laser-lovers] LN03 report

laser-lovers@uw-beaver (03/13/85)

From: lucas@cmu-psy-a (pete lucas)

I have had access to an evaluation unit of the LN03 for the past two weeks.
Here's a report:

GENERAL
The LN03 is an 8 page/minute 300 dpi laser printer recently announced by DEC.
It is based on a marking engine built by Ricoh and a controller of apparent
DEC design.  It comes with a serial interface switch settable  up to 19.2K, 7
or 8 bit ASCII with  xon/xoff flow control.  The printer lists for $4195.

MARKING ENGINE
Unlike the Canon engine with which it competes, the Ricoh marking engine
does not have an integrated toner cartridge/imager.  Rather, it uses
separate toner cartridges (actually, just dumps toner into a bin -- claimed
to be good for 3000 copies) and a user-replaceable organic imager belt
(rated at 10000 prints).  When you replace the belt, you also replace a pair
of corona wire cartridges, a glass imaging window, a quenching lamp (really
a stick with a row of LEDs), and an ozone filter.  This all sounds bad, but
its really *very* simple (just open an access door, slide out the old and
slide in the new) and there is excruciatingly detailed documentation.  The
printer tells you when it is low on toner or needs a new belt.  Its slightly
more complex than with the Canon, but in principle at least, seems more
cost-effective. The whole thing shouldn't take more than 10 minutes every
10K pages, at least after the first time.
The best news is the paper handling:  Both the input and output trays hold up
to 250 sheets of 8.5x11" or A4 paper (switch selectable).  The prints come
out at the top and are delivered to the output tray face down and PROPERLY
COLLATED.  The paper path is straightforward and seems to be robust to jams.
The paper takes a sharp turn around the fuser and so tends to come out
somewhat curled.  There is no provision for feeding envelopes or odd sized
paper.
Image quality was consistently excellent, although we only put about 1000
sheets through the machine on a new belt.

CONTROLLER
The controller is band-buffer based, there is no full bitmap.  Like most
recent DEC printers, the LN03 uses ANSI escape sequences as its page
description protocol.  With a few minor exceptions, the commands are a
compatible superset of the LN01's command set, although several of the
defaults are different.  We had no trouble making SCRIBE LN01 support work
with the LN03.  It is also more or less compatible with the LA100 and LQP02
dot matrix printers.

FONTS
The printer comes with 16 resident fonts, all fixed width, including
multinational characters, vt100 line drawing, and some technical stuff.
There is support for both ROM and downloaded fonts.  There are two cartridge
slots which can be used either for ROM fonts or expansion RAM. Each RAM
cartridge is 128kb and lists for $479.  Looks like you need a RAM cartridge
to do anything interesting, but one should normally be enough.  DEC has
announced a font library from Compugraphics in both soft and ROM form.
Fonts are in a new "DEC Common Font Format" which they say they will publish
(did not come with the "preliminary" programmers manual which came with our
unit). This means that LN01 (read Xerox 2700) fonts are not usable with the
LN03. The printer is capable of rotating portrait fonts to landscape
orientation (and vice versa) assuming enough memory is available.  They
claim to support up to 24 fonts/page.  You can query the printer for status
of available fonts and selectively delete them to make room for new ones.
Error status reports are also available.

GRAPHICS
You can download bitmaps to the LN03 using the "Sixel Graphics" protocol (6
bits at a time converted to a printable ASCII character).  You can select
one of several aspect ratios and an arbitrary scale factor, but the maximum
resolution in sixel mode is 150 pixels/inch.  There's a catch, however:
at high resolution, it is possible to run into band-buffer complexity limits,
so it is NOT the case that any arbitrary bitmap is printable.  We were able to
produce band-buffer errors with some test patterns of only medium complexity
when printed at 150dpi.  Minor positioning or orientation changes tended to
make these problems go away, but this was unpredictable.  We never
observed complexity problems with any "real life" screen dump from a bitmap
display, but it is definitely a severe limitation when attempting full
resolution graphics.
There are escape sequences for producing vertical and horizontal vectors of
any thickness, but thats it as far as graphics primitives go.  Beyond that,
you have to send a bitmap or font mosaic.

SUMMARY
The LN03 isn't much of a graphics device, but as a distributed printer for
TEX or SCRIBE class document production, it should be just dandy.  It is
certainly a big step up from the HP Laserjet for not much more money.

With a full bitmap controller, it looks like the Ricoh engine would make
a nice printer.

				-Pete Lucas

laser-lovers@uw-beaver (03/16/85)

From: ihnp4!utzoo!henry@uw-beaver.arpa

> The LN03 isn't much of a graphics device, but as a distributed printer for
> TEX or SCRIBE class document production, it should be just dandy.  It is
> certainly a big step up from the HP Laserjet for not much more money.

Note that the LaserJet can indeed do moderately-decent typesetting,
using Textware International's software.  We have had people (admittedly
not typesetting professionals) mistake the output for photocopies of
phototypesetter output.  It looks considerably better than the output
from the local Imagens, probably because HP's fonts are cleaner.

I agree that downloadable fonts and the paper-handling improvements are
significant, although (as I've described recently) face-down stacking
is pretty trivial to arrange for a LaserJet.  But it's not quite so much
of a "big step" as you would think; people who use LaserJets only as
daisywheel replacements are missing the potential of the machine.

				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,linus,decvax}!utzoo!henry