[comp.lang.postscript] The Printer Had A Hard Disk

woody@rpp386.cactus.org (Woodrow Baker) (11/09/89)

In article <1014@umigw.MIAMI.EDU>, aem@mthvax.cs.miami.edu (a.e.mossberg) writes:
> In article <8911081356.AA26268@terra.oscs.montana.edu> iphwk@terra.oscs.montana.edu (Bill Kinnersley) writes:
> >        I just received a brochure from NEC describing the LC 890XL
> >PostScript printer.
> 
> >        It comes with a 68020 processor, 4 Mb of RAM, upgradable to
> >8 Mb, and an optional 20 Mb hard disk.  The disk "connects to the
> >printer's built-in SCSI interface.  It increases font storage and
> >allows users to cache multiple fonts and overlays."
> 
> Sounds like another Canon engine/Apple controller printer. 
> 
> The Apple LaserWriter we have (NTX) also has the hard disk
> option available.
> 
> I suspect that it's useful for very very few people to have a hard



Well, the hard disk is usefull for more than fonts.  Postscript has a feature
that is called a font 'cache'.  What happens is that when you scale a font and
use the letters, the filled in bitmaps are stored in a font cache, and if you ask
for a letter that has already been rendered, Postscript will grab the bitmap
from the cache, thus speeding the operation up drasticaly.  The old laserwriters
only had 1.5 meg total, which means that program space, scratch space and font
cache had to fit in .5 meg.  Newer printers have more memory, so they run faster.
They cache more of thier fonts.  The cache keeps the most recently used fonts.
If you have a document with a small number of small fonts, you will find that
the first page after powererup takes significantly longer than all other pages
until major font changes occur.  The HARD DISK is used to permanently cache
fonts.  If you have a hard disk, and you have used a font at a particular
point size, the bit map will be retrieved off the hard disk, and used rather
than re-rendering a font.  This speeds things up SIGNIFICANTLY.  The major 
problem is that the hard disk and os are extremely flakey.  Don Lancaster
report many problems.  The good side of this is that Don has published
a routine to retrieve the bit maps off the hard disk,and return them to the
host computer.  this means that you can now get a bit map of a font that
adobe has generated, and use it for a screen font.

gerry@dialogic.UUCP (Gerry Lachac) (11/09/89)

In article <1014@umigw.MIAMI.EDU> aem@Mthvax.CS.Miami.Edu writes:
>
>I suspect that it's useful for very very few people to have a hard
>disk for fonts.
>

Actually this is very far from being true.  A hard disk is extremely
useful for a Postscript printer. Remember, every time you print
something, the printer has to construct a "bitmap" from the font
outline.  This sucks up processor time.  With a hard disk, you can
build all the bitmaps that you use, and instead of constructing them
each time, you fetch them from the disk. This really speeds things up.

Don Lancaster had a good article in an old Computer Shopper about this.

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