Path: utzoo!attcan!uunet!mcsun!cernvax!chx400!ethz!czychi
From: czychi@ethz.UUCP (Gary Czychi)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Page Rectangles (Reply part two)
Message-ID: <6156@ethz.UUCP>
Date: 8 Oct 90 12:22:59 GMT
References: <10585@goofy.Apple.COM>
Reply-To: czychi@bernina.UUCP (Gary Czychi)
Organization: ETH Zuerich, Switzerland
Lines: 93


(I'm sorry, I have to submit this reply in several parts because
I can't figure out how to do it in one part. The whole text is
rejected by my mailer because its so long).

Part two follows:


> 
> David Casseres
>      Exclaimer:  Hey!


Meanwhile I've got a mail from Sean Parent <sean_parent.snarkmail_l_z>. He
says (I hope I am allowed to quote him):

> Once upon a time an Apple engineer wrote some code to calculate the
> page size for the ImageWriter. Unfortunatly, he didn't realize that
> his calculations where poor and didn't always make best use of the
> machine. The calculations where incorrectly based on the printers
> resolution of 144dpi instead of 72dpi. Well, then along came the
> LaserWriter and adjusted the same code without fixing this bug to
> 300dpi (and the problem got worse) and constrained it to the memory
> limitations of the LaserWriter Classic. Well, then the ImageWriter
> code was adjusted to support the ImageWriter wide carrige. Now the
> driver decides to go into wide carriage mode if the paper is large
> enough and you have wierd dead zone in widths with page sizes from 9
> inches in width up. Then this code was adjusted for the ImageWriter LQ
> (it still has that same original bug) and so the LQ ImageWriter driver
> printable area never matchs the ImageWriter's (even though there is no
> reason why they couldn't) and you have the same wierd dead zones even
> though you know you have a wide carriage printer. Well, the
> ImageWriter code was also used in the LaserWriter SC adjusted for the
> memory requirements of that device with all of the same original bugs,
> yet new and different printable areas. This is one of the worst cases
> of propagating bugs that you will ever see. Unfortunatly it cannot be
> fixed in existing drivers without reformatting everybodies documents.

> Sean Parent
> "Quality unattainable in a reasonable amount of time."


In article <52424@brunix.UUCP> omh@cs.brown.edu (Owen M. Hartnett) writes:

> > Minimum margins are determined by the printer hardware, and they are
> > indeed essentially equal on the left and right.
> >
> 1) Microsoft products can write to areas which are within the "minimum
margins."
> 
> Thus, we can infer that the minimum margins give an area which can be
imaged
> given any possible image configuration, or at least, any *reasonable*
> imaging configuration.  (by image configuration, I mean any of a set of
all
> possible quickdraw or postscript calls that cause imaging only inside said
> margins.)  I.E. we will probably never encounter errors given that we
confine
> our output to said areas.
> 
> -Owen
> 
> Owen Hartnett                           omh@cs.brown.edu.CSNET
> Brown University Computer Science       omh@cs.brown.edu
>                                       uunet!brunix!omh


Let's summarize:
There *is* something wrong with the calcuation of the page rect, but it
wouldn't be opportune for Apple to change it in the near future. And as far
as I know, there's no patch which can be applied to the driver(s) to change
it to more reasonable values.

BTW, the memory of the LW SC can hold 1.048.576 bits. How much room is left
in there for the actual page? The page is prepared in the Mac itself, so in
the printer should be enough room for the *very big* page rectangle.


Thanks a lot for all your replys and efforts,

Gary


        Gary T. Czychi             University of St.Gallen, Switzerland
	  
                czychi@csghsg52.BITNET               (preferred)
                czychi@bernina.ethz.ch.UUCP          (CZYCHI@ETHZ.uucp)

		        Tel.: --41 / 71 / 57 17 22


---- end of part two and end of this reply.  (I guess I like the Mac more
than Unix... :-) -----