Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!clyde.concordia.ca!rutgers!umn-d-ub!umn-cs!nis!ntmtka!steve
From: steve@ntmtka.mn.org (Steve Wahl)
Newsgroups: comp.sys.amiga
Subject: Re: Non-Zorro slots in the Amiga 3000
Keywords: 3000 slots
Message-ID: <1935@ntmtka.mn.org>
Date: 12 Dec 89 17:05:56 GMT
References: <5906@ubc-cs.UUCP> <3751@convex.UUCP> <5936@ubc-cs.UUCP> <3854@convex.UUCP>
Reply-To: steve@ntmtka.mn.org (Steve Wahl)
Distribution: na
Organization: Northern Telecom Inc., Minnetonka,MN
Lines: 57

As I recall, this whole discussion has to do with whether or not there will
be IBM-PC type slots int the 3000, and the argument has been "Probably not,
because of the extra room taken by the 32 bit connections on the slots."

How about this solution:  (NOT to scale)

|----------------------------------------------------------------------| B o M
|          16-bit Zorro          32-bit Zorro extension                | a f a
| ============================ ==========================              | c   c
|                                                                      | k   h
| ============================ ==========================              |     i
|             (Repeat N times)                                         |     n
| ============================   ============ ======================   |     e
|      16-bit Zorro  (Bridgecard Slots)  AT  & XT bus                  |
| ============================   ============ ======================   |
|                                                                      |
|                                ============ ======================   |
|                                      (AT/XT Bus in whatever size)    |
|                                             ======================   |
|                                                                      |
				.
				.
				.

|                                                                      |
|----------------------------------------------------------------------|

Of course, there would have to be some kind of logic so that the 16-bit
zorro slots are mapped only into one 16-meg portion of the 32-bit address
space.  This would have to be possible to use older Zorro boards,
wouldn't it?

Due to the opinions that I've heard in this group regarding the utility
of a bridgeboard (which I agree with - I don't see a reason to get one
for my 2000, and I don't know what I'd do with my 5.25" hard drive),
I don't think anyone is going to argue that the bridgeboard has to be
connected to the full 32 bits of the Zorro bus; I'm sure it can get by
on a 16-bit port.  

Does anyone see anything wrong with this scheme?

Personaly, I'm not sure whether or not the 3000 will have a PC Bus or
not, but I do think it is possible.  As to whether it would be a desired
feature, I must point out that for *some* reason Sun Microsystems has both
a software and hardware option for (some of?) their Sparc Stations (and
maybe other systems) to run MS-DOS based software.  My only guess is that
there are some executives who like to buy the most expensive computers
that can run 1-2-3 and dBase :-).

These are only my opinions, of course!

--> Steve
-- 
Steve Wahl
Northern Telecom, Inc.       (612) 932-8079
S-100, 9701 Data Park        steve@ntmtka.mn.org
Minnetonka, MN 55343         {rosevax,bungia}!ntmtka!steve