thomas@utah-gr.UUCP (Spencer W. Thomas) (10/03/83)
Ah, but can you print rasters on them? You can't on our Xerox 2700, at least not yet (I think they claim this might be possible in the future, if memory prices go WAY down). =S
ckm%sch-thor@BRL.ARPA (10/04/83)
This message is empty.
dmmartindale@watcgl.UUCP (Dave Martindale) (10/06/83)
We have several Versatec plotters here and two Imagen printers, so I will try to compare them for the benefit of the readers. The Versatec requires little maintenance other than regular cleaning and changing of toner, premix, etc. It just sits there and runs until it breaks. The Canon laser engine requires having its drum replaced occasionally, corona wires adjusted, and a number of other apparently- finicky mechanical adjustments. Imagen has been very slow in shipping the specialized tools needed for these adjustments. On the other hand, day-to-day operation of the Imagen involves feeding it paper, premix, and toner concentrate as it asks for them (there is a panel with LEDs indicating which one is low) and clearing the occasional paper jam. With the Versatec, you have to monitor quality yourself, press the "premix add" button when needed, and change the premix when you judge it's needed. Output quality of the Imagen is clearly better. The resolution is higher (320 vs 200 dpi) and there are no gaps between dot rows where the Versatec started and stopped, nor black smudges where the image was overdeveloped due to the paper stopping for too long in the Versatec. For Troff output, the Imagen seems the winner. It is driven over a serial line, and the scan conversion of the characters into raster form is done in the Imagen, offloading the host. The output is on standard 8 1/2 by 11 paper, in the correct sequence (the last page is printed first). The Versatec requires scan conversion to be done in the host, and the busier the host is, the more problems you will have with uneven output quality due to the Versatec pausing. For graphics, the Versatec still seems to win, though that may change. It is an extremely dumb device; you just pass it bits. This makes it easy to generate whatever image your heart desires. Our first Imagen was completely incapable of doing full-page graphics; it just didn't have enough memory. We have a newer model now, and have just upgraded the older one (the upgrade instructions were not complete, we had to call Imagen to find out that the two boards in the end slots should be moved) and they are supposed to be capable of graphics. However, we don't have any software in place yet to do this. Some machines run the Berkeley VLSI tools; they already support the Versatec as an output device. I know of no such support for the Imagen. I do not know if the Imagen is even capable of doing full-page grey scale images, which require individual control of every dot on the output page. Certainly, transferring this much information over a serial line will take forever. The Versatec's DMA interface runs at the same speed regardless of what is to appear on the page. Dave Martindale University of Waterloo
tut@populi.CC.Berkeley.ARPA (10/09/83)
Several recent questions about hooking up a Versatec V80 made me wonder. Do people still buy Versatec printers rather than laser printers? There are several laser printers available that produce output somewhere between a Versatec and a phototypesetter in quality, but nearer to typeset quality. They cost under $25K, and make impressions on plain bond paper, for which the fixed cost is about $.025 per page. One company (Imagen in Mtn View, CA) provides host software interfaces for troff, ditroff, TEX, Scribe, and Tektronix 4014. Bill Tuthill
guy@rlgvax.UUCP (10/10/83)
Another point of comparison between electrostatic printer-plotters and laser
printers: at my previous site we had a Gould electrostatic, and if you didn't
keep the computer room at the humidity level of the Amazon rain forest the
paper dried out and the print quality went downhill. Also, electrostatic
printer-plotters require expensive coated paper, which goes brown if you
leave it in the sun too long (yes, regular paper will do that eventually too
but the time-to-failure is a few orders of magnitude greater) and which goes
all to h*ll if it gets wet.
Still, it is nice to be able to do your *own* formatting of raster images and
send them to the printer, instead of being forced to use the manufacturer's
idea of how things should be formatted. Our Office Power office automation
system has a word processor which has its own definite ideas about how to
format lines of text, and the printers which will do it for you are at best
wasting their effort trying to be smart (if you can give them direct commands
and do it yourself) and at worst useless (if you are forced to live with their
way of doing tabs and line-spreading; they don't do everything we need them to
do). Printers should either be 100% dumb or 100% intelligent (i.e. either
the host computer can tell them where to put the characters or dots or the
computer in the printer should be programmable so you can control where it
puts the characters or dots).
Guy Harris
{seismo,mcnc,we13,brl-bmd,allegra}!rlgvax!guyFIGMO%kestrel@sri-unix.UUCP (10/12/83)
From: Lynn Gold <FIGMO@kestrel> We have a Versatec which we use for TeX. It sure looks like it's supporting rasters! --Lynn -------
gwyn%brl-vld@sri-unix.UUCP (10/19/83)
From: Doug Gwyn (VLD/VMB) <gwyn@brl-vld> Although I like Versatecs pretty well, one thing that needs to be considered in some applications is that the coated paper surface is hard to write on (nearly impossible with certain types of pens).