Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!olivea!apple!agate!ziploc!eps
From: eps@toaster.SFSU.EDU (Eric P. Scott)
Newsgroups: comp.sys.next
Subject: Re: NeXT and non-laser printer (again)
Message-ID: <880@toaster.SFSU.EDU>
Date: 6 Oct 90 03:52:55 GMT
References: <13115@cs.utexas.edu>
Reply-To: eps@cs.SFSU.EDU (Eric P. Scott)
Organization: San Francisco State University
Lines: 63

In article <13115@cs.utexas.edu> tph@cs.utexas.edu (Pow-Hwee Tan) writes:
>  What I was thinking is that since the NeXT screen is a bit-mapped
>display, there must be routines in the NeXT OS that does the
>mapping of PostScript commands to bitmaps (rasterizing).  Also,
>I presume that the NeXT laser printer does not do much 
>PostScript processing, with much of it done in the NeXT CPU.

All of it is done in the NeXT CPU.  The NeXT Laser Printer is
so inexpensive because it's basically a marking engine with a
high-speed interface.

>Since the printer's resolution in terms of dpi is different from
>that of the MegaPixel Display, the mapping routines probably accept
>a "dpi" parameter.

It's called Resolution, but it's not quite as accessible as one
might like.

>  Therefore, wouldn't it be easy to write a driver to utilize
>these PostScript-to-Bitmap functions and "bit-blast" the image
>to a non-laser printer, such as a DeskWriter with 300 dpi?

Well, sort of.  First of all, doing this is subject to the
conditions of the NeXT Software License Agreement:

	The NeXT Software is intended to be used to generate
	screen displays with resolutions of less than 150 dots
	per inch on a NeXT Computer and to print images with
	print resolutions of up to 600 dots per inch on a NeXT
	Printer.  You agree not to make use, directly or
	indirectly, of the PostScript software included with the
	NeXT Software to print bitmaps with print resolutions of
	150 dots per inch or greater, or to generate fonts or
	typefaces, other than on a single NeXT Computer in
	conjunction with a single NeXT Printer.  You are free,
	however, to transmit and print PostScript language files
	you create with the NeXT Software on any printer.
	(_Registration, Warranty, and Software License_, 1026.02,
	2/90)

(This is for 1.0a--I don't know what the 2.0 Agreement will say.)

Also consider the following:

	(1) The NeXT assumes a square aspect ratio.  Most
	    low-cost printers (such as commonly used on PCs)
	    are not square.  Admittedly, this isn't a
	    problem for you.  I don't know what's done in
	    2.0 to support 100x200 FAX rendering.
	(2) windowdevice[round] and printerdevice do some
	    subtly different things.
	    *you can't use printerdevice unless you have a NeXT
	    Printer attached*  It generates a limitcheck error.
	    (This is documented in Chapter 24 of the SysRefMan
	    and trivially verified.)  It so happens that windows
	    believe they're 72dpi (even though they're displayed
	    at 92dpi), so hacks like iwscript aren't *that*
	    difficult to write.  Of course, you need to be
	    logged in with Public Window Server enabled (unless
	    someone wants to reveal the secret to how npd gets
	    around this).

					-=EPS=-