Path: utzoo!attcan!uunet!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.arch
Subject: Re: Problems with NeXT (25 MHz NuBus clock discussion)
Message-ID: <5155@cbmvax.UUCP>
Date: 31 Oct 88 23:23:39 GMT
References: <461@ma.diab.se>
Organization: Commodore Technology, West Chester, PA
Lines: 28

in article <461@ma.diab.se>, pf@diab.se (Per Fogelstr|m) says:
> 
> One thing that strikes me:  How many slots can NuBus have when it uses this
> high clock rate ??  

From the BYTE photos, the NeXT layout looks like this:

	+---+---+----------+---+---+
	|   |   |          | N |   |
	|   |   |  Disks   | e |   |
	|   |   |          | X |   |
	|   |   |          | T |   |
	|   |   |          |   |   |
	|   |   |          |   |   |
	|   |   |  Power   |   |   |
	|   |   |          |   |   |
	+-1-+-2-+----------+-3-+-4-+

Having the disks in the center might be prettier, but you've got to pay a penalty
in line lengths going to slots 1 and 2.  Of course, this forces you to deal with
a foot long backplane even if it doesn't have that many real slots.  The limit
on NuBus anyway is 16 slots, though there's a pretty good chance you's have a
hard time running a 16 slot NeXTBus machine, especially given that goofy NuBus
asymmetric clock.
-- 
Dave Haynie  "The 32 Bit Guy"     Commodore-Amiga  "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: D-DAVE H     BIX: hazy
              Amiga -- It's not just a job, it's an obsession