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Article #3569

Re: pmmu

#3569
From: Ivan Cavero Belaunde
Date: Fri, 25 Aug 1989 18:50
56 lines
3409 bytes
In article <4804@merlin.usc.edu> jchau@girtab.usc.edu () writes:
>HI everyone

Hi yourself, and welcome!

>  I started to search for an upgrade path for my Mac II but
>to my dismay, the cost is fantastic.... just like buying a new machine.
>
>With such financial constraints, I can only hope to add a PMMU on my Mac
>as well as the high density drive.  I like to know where I could get
>a PMMU at a reasonable price.  Also, while reading other postings,
>I kept coming across the 32 bit quickdraw.  I have a 8 bit graphic
>card with the apple RGB color monitor with my system. I was hoping
>that someone out there would be able to tell me the functionality of
>the 32 bit quickdraw and the ways and means to get it.

Well, the advantages of the IIx over the II are:
	1) 68030 instead of 68020 - built in PMMU.  This is solved by
		adding a PMMU to the II.  Since it is built in into the
		CPU in the IIx, there  is one less wait state and it
		is therefore marginally faster (see performance, below).
	2) Slightly improved performance - the IIx is about 15% faster than
		the II, partially because of the wait state mentioned before,
		and partially because it has separate data and instruction
		caches.  This performance gap is easily closed with
		Orchid's MacSprint II cache card for the II (~$299 list).
	3) FDHD capability - the IIx comes with an improved disk controller
		chip (the SIWM) which allows it to control a high density
		3.5 inch drive, giving you twice as much storage on a floppy,
		as well as the capability to read and write to and from
		IBM 3.5 disks.  The FDHD upgrade should do the trick.
		I am not 100% sure on this next part, but it is my
		understanding that the FDHD upgrade also allows the II to
		use 4MB SIMMs, since the SIMM slots in the II are slightly
		nonstandard.  The IIx, cx, and SE30's slots are fully
		compatible with 4MB SIMMs.
	4) ROM SIMMs - Nice for system software upgrades, but not a vital
		consideration.  No way to get this short of getting the
		expensive upgrade.

About getting a reasonably priced PMMU: contact Ted Blakeley
(mblakele@jarthur.claremont.edu).  He's collecting names to make a quantity
net.order for PMMUs from Motorola.  I think the price he was quoted was $200
for 1-4 chips, so with the amount of people involved the price could go
down significantly (tho' $200 ain't bad at all).

Re: 32-bit quickdraw.  It allows you to manipulate 32-bit color images on the
Mac, giving you photographic quality images.  32BQD, however, just supplies the
system software to work with these images - to take advantage of it, the
software you use must specifically use 32BQD (and there ain't much out there
yet).  The nice part, I think, is that it also gives you the ability to
halftone color printouts and stuff like that.

-Ivan

Internet: captkidd@athena.mit.edu
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!apple!bloom-beacon!athena.mit.edu!captkidd
References: <4804@merlin.usc.edu>

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Path: arc1-ca.pugleaf.net!utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!apple!bloom-beacon!athena.mit.edu!captkidd
From: captkidd@athena.mit.edu (Ivan Cavero Belaunde)
Newsgroups: comp.sys.mac
Subject: Re: pmmu
Keywords: Mac II, Pmmu, 32 bit Quickdraw
Message-ID: <13820@bloom-beacon.MIT.EDU>
Date: 25 Aug 89 18:50:55 GMT
References: <4804@merlin.usc.edu>
Sender: daemon@bloom-beacon.MIT.EDU
Reply-To: captkidd@athena.mit.edu (Ivan Cavero Belaunde)
Distribution: usa
Organization: Massachusetts Institute of Technology
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