Subject: Re: None
To: None <>
From: Joe Torre <>
List: amiga
Date: 12/04/1995 17:00:08
On Sun, 3 Dec 1995 wrote:

> >>>>> "Joe" == Joe Torre <> writes:
> Joe> I dont know if the older SunOS could run on *any* Amiga, because
> Joe> you would need the 68010 for sure. But an A500 can easily have
> Joe> 1meg ram, and the 68010 is a drop in replacement for 68000 Amiga
> Joe> wise.
> 	The Sun1's started using 68000's according to the hardware
> FAQ, but not many were made.
> Joe> However, The Sun 2 is a 68010 for sure.  Sun Model 2/120 = 10mhz
> Joe> 68010-1meg ram 2/170 = 10mhz 68010-2meg ram
> Joe>  The 68010 has a way of emulating virtual memory by traping
> Joe> access to memory areas not physically present by using the vector
> Joe> base register (VBR).
> 	If I'm not mistaken, the VBR allows you to have a duplicate
> set of interupt vectors and use them instead of the hardwired ones
> (which lie in the first few pages of RAM).  To the Amiga, this meant
> that your interupt handing vectors could be in FAST ram instead of
> chip, which made things faster.
Yep. 68000 systems owners seldom regret the simple swap-upgrade to 68010.
"Game XYZ wont get past the copy-protection anymore" or 
"The laser printer LED's are all funny and it wont print."
The MOVESR command is different on the 010 (this big problem is fixed on 
amiga systems with a command TRAPMOVESR (on aminet))
 "self-modifying code" when caught in the 010 loop mode ( a kind of 3 
instruction cache ) would execute as self-munging code.

> 	However, even if what you say is true, you still have the
> problem of REAL memory getting accessed and that what you're proposing
> would cause an interupt for every single virtual memory access.
> Joe> The Sun 3 has a 68020 CPU and 68451 MMU. Any Motorola 020 systems
> Joe> could be upgraded to 030 by installing a hudge jumper plug in the
> Joe> 68451 socket and a mezzinine board with an 68030 in the 68020
> Joe> socket. This "upgrade" also removed one waitstate on any address
> Joe> translations and made quite an improvement. Math coprocessors on
> Joe> 020 systems were with 68881 (12-33Mhz) and 030 systems used the
> Joe> 68882 which allowed concurent instruction execution with the
> Joe> 030. 50mhz 68882 can be installed where a 12mhz 68881 once was
> Joe> (perhaps with a 60mhz xtal clock!) and the floating point
> Joe> performance is *quite* improved. Render ho!
> 	In a similar vein, if you took a 68000 or 68010 and placed it
> on a daughter board, coupled a MMU with it and plugged it into the
> 68000 socket on an A500, it would be closer to the old suns.  That
> wouldn't solve, however, the other hardware differences.  Besides,
> when you think about it, that's what you're doing when you put an 030
> or 040 board into an A500 or A2000.
> Dave.
Yes. Thats why a 040 @ 40mhz with 16megs beats *any* motorola based Sun.
Thats why we are running Net-BSD on Amigas. It hauls!
....Or was it the zorrow slots and that Suns dont run Workbench 3.1??? 

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