[fa.laser-lovers] Imagens on ethernet unusual practice?

laser-lovers@uw-beaver (10/11/85)

From: Christopher Schmidt <SCHMIDT@SUMEX-AIM.arpa>

	We have five Imagen printers on various ethernets and can print on
any printer from any host.  In other words, it is the usual practice here!
	They tend to run at the full duty cycle of the print engines,
too.  (Our fastest at the moment goes 10 pages per minute, but I see
no reason why our 12/300's on order won't run at the full 12 pages per
minute.)  When printing a 30 page document, for example, the 30th page
is usually processed before the 5th page is printed.  This is fast
enough that we don't even consider the non-pipelined pagereversal
option to have a significant effect on our printer throughput.
--Christopher
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laser-lovers@uw-beaver (10/14/85)

From: Robert Morris <ram%umass-boston.csnet@CSNET-RELAY.arpa>

If you start doing graphics, especially bit maps, you will find that
even the ethernet printers may not run at full speed, although for
bitmaps the communications time is so dominant that 9600 baud serial
lines prove painful. For higher level graphics the complexity of
the graphics determines the throughput, but imagen printers seem to
be able to do pretty well for realistic documents (imagen's release 2.2,
the first guaranteed to be able to print a page of arbitrary complexity,
seems to be about 10% slower when you invoke this guarantee than when
you don't).

Using the automatic page reversal is, to my mind, somewhat dangerous
in all environments except plain text using printer resident
fonts. Since the printer must accumulate all the pages before printing
any, it seems likely that you can fill printer memory with pending
impress commands and get in trouble when you need it for complex
pages. I have no experience of this, since we don't default to
page reversal on, but expect the host software to send pages in 
last page first order.

bob morris
umass/boston
and Interleaf, Inc.