Path: utzoo!attcan!uunet!cbmvax!daveb
From: daveb@cbmvax.UUCP (Dave Berezowski)
Newsgroups: comp.sys.amiga
Subject: Re: 1.3 Printer Drivers
Message-ID: <4695@cbmvax.UUCP>
Date: 9 Sep 88 16:55:16 GMT
References: <388@richp1.UUCP> <371@quintus.UUCP>
Reply-To: daveb@cbmvax.UUCP (Dave Berezowski)
Organization: Commodore Technology, West Chester, PA
Lines: 46

In article <371@quintus.UUCP> pds@quintus.UUCP (Peter Schachte) writes:
>While we're on the topic of 1.3 printer drivers and ProWrite, I too have
>ProWrite 2.0, and I have an Epson JX80 Printer.  This printer is capable
>of pretty high resolution in it's best graphics mode (I think it's 360
>dpi horizontally, although of course the pins are bigger than that, so
>it'll never look as good as that number would indicate).  The hitch is
>that you have to make 2 passes for each line (one for odd pixels, and
>one for evens).  The 1.3 driver only makes 1 pass, so it doesn't get the
>best resolution the printer can deliver.
>
>So the questions are:
>
>1)  Am I confused about the 1.3 driver or Epson X printers?  Is there
>    some way to get it to make two passes?
>
	No, not without altering the current code.  This strangness of
only printing every second dot is a hardware/software limitation of SOME
printers.  It is a hardware limitation in that they physically can't do
it without over heating the print head.  It is a software limitation in
that printers which have this hardware limitation SHOULD (in my opinion)
make up for it in software.  In other words, they printer itself should
be smart enough to know that it has to do a second pass.  There are
some printers like this; the Nec line of printers appears to do this.
The trouble with trying to write a printer driver (like the EpsonX)
that works over a wide range of printers is that you don't know if the
printer is going to have the abovbe smarts or not.  If you code the smarts
into the printer driver then some printers will be doing twice the work.
If you don't then some printers will miss every second dot.  Its a tough
call.

>2)  Has someone built an Epson X printer driver that gets better quality
>    than the 1.3 driver?  If so, can I get it?
>
	Not that I'm aware of.  However, we did give you interleaved
densities under V1.3 (ie. getting 216 y dpi out of a 72 y dpi printer).

>3)  What do I read to find out how to write one myself?  Can I get my
>    hands on an example 1.3 printer driver?
>
	The DevCon (Amiga Developer's Conference) notes contained an
article entitled 'Writing a V1.3 Graphics Printer Driver'.  This article
was also published in a recent issue of AmigaMail.  CATS will be releasing
disks with sample code for some of the V1.3 drivers to qualified
developers.

	Regards, David Berezowski