Subject: Re: None
To: John Shardlow <john@iceberg.demon.co.uk>
From: Joe Torre <joetee@netcom.com>
List: amiga
Date: 12/03/1995 07:41:14
On Sat, 2 Dec 1995, John Shardlow wrote:

> Hi dgilbert@jaywon.pci.on.ca
>    In <9512020145.aosl@jaywon.pci.on.ca> you wrote:
> > 
> > Actually, the timeline for Sun was: Sun1 and Sun2 (68000) then Sun3
> > (68020 and a few 030).  Then Sun made some i386 boxes.  Then Sun4
> > (sparc).
> 
> How did they run Unix on a 68000 processor? Did it have no virtual
> memory? If so maybe old versions of SunOS could run on any Amiga?
I dont know if the older SunOS could run on *any* Amiga, because you would
need the 68010 for sure. But an A500 can easily have 1meg ram, and the 68010
is a drop in replacement for 68000 Amiga wise. 

However, The Sun 2 is a 68010 for sure.
  Sun Model 2/120 = 10mhz 68010-1meg ram
            2/170 = 10mhz 68010-2meg ram

 The 68010 has a way of emulating virtual memory by traping access to 
memory areas not physically present by using the vector base register (VBR).
 
The Sun 3 has a 68020 CPU and 68451 MMU. Any Motorola 020 systems could be 
upgraded to 030 by installing a hudge jumper plug in the 68451 socket
and a mezzinine board with an 68030 in the 68020 socket. This "upgrade"
also removed one waitstate on any address translations and made quite an
improvement. Math coprocessors on 020 systems were with 68881 (12-33Mhz)
and 030 systems used the 68882 which allowed concurent instruction 
execution with the 030. 50mhz 68882 can be installed where a 12mhz 68881
once was (perhaps with a 60mhz xtal clock!) and the floating point 
performance is *quite* improved. Render ho!

Now if I can just get NetBSD 1.1 installed on my 68040 A2000......!!!!

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