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From: rbp@investor.pgh.pa.us (Bob Peirce #305)
Newsgroups: comp.sys.next
Subject: Postscript output resolution - again
Message-ID: <1991Mar7.134221.4577@investor.pgh.pa.us>
Date: 7 Mar 91 13:42:21 GMT
Reply-To: rbp@investor.pgh.pa.us (Bob Peirce #305)
Organization: Cookson, Peirce & Co., Pittsburgh, PA
Lines: 35

I posted this once before but didn't get the response I needed.  I was
told that under 1.0 resolution out the serial port could be 150 dpi and
under 2.0 it can be 900 dpi.  However, nobody has been able to point me
to any reference where this is clearly stated.  Additionally, I am also
looking for a reference that will tell me how to set the output
resolution.  I have a 68030 cube with the complete 1.0 software release
and I will be upgrading to a 68040 with the complete 2.0 software
release.  I am looking for chapter numbers or keywords that will provide
this information.

Specifically, I am modifying Eric Scott's iwf program to drive an Epson
LQ-510 under 1.0.  The output resolution is about 60-80 dpi.  In looking
through the function calls, I have been unable to find any place where
this resolution is set.  If it is not set, why isn't it 150 dpi? 

It may be coincedence, but the bit pattern going to the filter works
correctly when my Epson is set for 8-pin printing with 1/8" line spacing
-- 64 scan lines per inch.  Horizontally, if I understand Eric
correctly, there are 2-bits/pixel, which determine four levels of grey. 
Eric assumes any grey is black, so the two bits are converted into a
black or a white pixel for printing.  This also works correctly when fed
to the filter modified for the way Epson fires its pins.

As a result, I have a program that works, but I do not understand why it
generates the specific resolution it does.  The output resolution is not
sufficient, but I don't know how to get more.

When I go to 2.0 I have the potential to get very good resolution but I
don't know what I will have to do to get it.  For that matter, I don't
even know what I will have to do to make this program work under 2.0. 
Certain threads in this group suggest it won't work at all. 

-- 
Bob Peirce, Pittsburgh, PA				  412-471-5320
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