Path: utzoo!attcan!uunet!husc6!mailrus!ukma!sean
From: sean@ms.uky.edu (Sean Casey)
Newsgroups: comp.sys.next
Subject: Re: How did they make the printer so cheap?
Message-ID: <10399@s.ms.uky.edu>
Date: 19 Oct 88 23:20:31 GMT
References: <0XKoeky00UgXM3T24=@andrew.cmu.edu> <73489@sun.uucp>
Reply-To: sean@ms.uky.edu (Sean Casey)
Organization: The Leaning Tower of Patterson Office @ The Univ. of KY
Lines: 29

In article <73489@sun.uucp> swilson@sun.UUCP (Scott Wilson) writes:
>I'm confused about something.  If
>the computer is going to build the image then for an 8 1/2 x 11" sheet
>at 400 dpi wouldn't you need 8.5x400x11x400 bits of memory in which
>the image is built?  This works out to be roughly 1.8 meg of memory
>(assuming I didn't screw up somewhere).  Does this mean that to
>compose a page for the printer the NeXT machine has to briefly use
>this much of its memory?

Not exactly. Imagen printer resident software, for example, allocates
memory in small blocks. I believe someone in the company told me 32
byte blocks. A block isn't allocated unless there is some black in it.
This is how a 512K 8/300 can reasonably print text and graphics.  I
suspect that text operations (i.e. fonts) are rasterized on the fly,
and don't require preallocations. This is only a guess.

This kind of technique would lend itself well to NeXT, and I suspect
that it's being done this way already.

My concern is how fast the Postscript processing is done. I understand
that Postscript is horribly cpu intensive. I'd hate to think of what
happens if your rasterization software goes virtual.

Sean
-- 
***  Sean Casey                        sean@ms.uky.edu,  sean@ukma.bitnet
***  The Hacker from Hell.             {backbone|rutgers|uunet}!ukma!sean
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