Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!rutgers!apple!casseres
From: casseres@Apple.COM (David Casseres)
Newsgroups: comp.sys.mac
Subject: Re: NeXT secrets
Message-ID: <126@internal.Apple.COM>
Date: 19 Oct 88 23:31:12 GMT
References: <15478@agate.BERKELEY.EDU> <1740@eos.UUCP> <532@gt-eedsp.UUCP> <9599@haddock.ima.isc.com>
Organization: Apple Computer Inc, Cupertino, CA
Lines: 50

In article <9599@haddock.ima.isc.com> suitti@haddock.ima.isc.com (Steve Uitti) writes:

>	For the Mac II, I have the General Computer Personal Laser
>Printer (PLP).  As with the Apple Laserwriter IISC, it connects to the
>computer via SCSI.  There is a processor in the laser printer, but it
>does not interpret Postscript (or anything else remotely complicated).
>It does have some memory, but I don't believe it has enough for
>anything like a page of bits (about a Megabyte is required).  As far
>as I can tell, the host rasterizes the stuff & sends it to the
>printer.  SCSI, the printer's CPU, and the Mac are quick enough to get
>the data to the drum so that it is not slower than having a CPU & RAM
>inside the printer.

For comparison, the LaserWriter IISC does have a MByte of RAM for a page
buffer.  Contrary to your last statement, for comparable modes of printing
the LaserWriter IISC is faster than the PLP -- unless you have some version
or configuration of the PLP that I haven't seen.  The PLP software uses the
disk as a buffer for the bitmap data to be printed, and this slows it down.

>	The advantages of Postscript (or some sort of language) in the
>printer are:
>1. The data sent to the printer is smaller.

Correct as long as the original data is not a bitmap.

>2. The host doesn't have to rasterize the document.
>	The advantages of having the host do it are:
>1. If there is a bug in the language, it can be fixed (it is just
>   software).
>2. More than one language can be supported (it is just software).
>3. It is cheaper.  A PLP goes for around $2K.  A Laserwriter Plus is $3.5K.

All true.

>	One argument goes that having the smarts in the printer allows
>the host to go on working while the printer prints, thus freeing the
>host.  For the Mac, this isn't generally true....

>...	Curiously, for the NeXT machine, it is more true.  The OS
>there is a true multuser OS.  Time spent degrades the performance of
>the rest of the machine (potentially, the network).

But actually it is true for the Mac, even without using a print server
on the net, if you print in the background under MultiFinder with the
LaserWriter.  There is
only a small degradation of foreground performance while printing.  The
time spent in spooling the print job in the foreground is very short for
most documents and most applications.

David Casseres