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From: rickk@hpvcfs1.HP.COM (Rick Klaus)
Newsgroups: comp.sys.mac
Subject: Re: LaserJet IIP Caveat
Message-ID: <780062@hpvcfs1.HP.COM>
Date: 26 Sep 89 21:38:11 GMT
References: 
Organization: Hewlett Packard, Vancouver, WA
Lines: 24

>Don't worry about the amount of memory the IIP contains. Our DeskJet
>has only 16K of memory and it prints out complete pages of graphics at
>300 dpi using the MacPrint driver.
>
>The driver divides the QuickDraw image up into bands in your
>Macintosh's memory. It sends the bands to the printer one at a time,
>not all at once. With 512K of memory, it just means that the driver
>can dump that much into the printer before it has to wait for some of
>it to be printed before sending any more.
>
   Wouldn't it be great if this were true?!!  The reason that DeskJet,
DeskJet+ and DeskWriter can operate with small amounts of RAM is that we
do not have to print an entire page at once.  We only have to have enough
memory for one pass of the printhead... about 16K!!  With laser printers, once
you start the engine rolling, you have to feed it real-time until the entire
page is printed, No pausing allowed!!  This is why the II-P will need a 1MB
memory upgrade to work on the Mac.
   Another misconception that is somewhat related to this discussion, is the
premise that "If it's a laser, it must be faster."  This is not the case, as
we raced a DeskWriter and LaserJet with the same driver and the DeskWriter
was much faster than the LaserJet!!

Rick Klaus
rickk@hpvcfs1