Subject: Re: Native boot [was Booter 1.8]
To: Chris Mason <cmason@map.com>
From: The Great Mr. Kurtz <davagatw@mars.utm.edu>
List: port-mac68k
Date: 12/21/1995 17:04:01
On Thu, 21 Dec 1995, Chris Mason wrote:

> Also, there is a ROM call to switch MMU modes.   Have a peek in IM V -- OS
> Utils:
> 
> PROCEDURE SwapMMUMode (VAR Mode:  Byte);
> CONST false32b = 0; {24 bit}
>       true32b = 1; {32 bit}
> 
> Will that solve the mapping problem??

I noticed that a couple of days ago in a FutureBASIC manual but couldn't 
find a way to crossreference it with anything outside of FB.  My 
Encyclopedia Mac Rom says it is Only for 256K ROM systems, but I don't 
think NetBSD will run on anything before the SE, anyway.  It also says 
the instruction was included for A/UX support.  Sounds pretty promising.  
I'm almost sure I've found out how to check the current setting.  From 
"new low mem": Location $0CB2 -- boolean reflecting current machine MMU 
mode.  Also, MMUFlutt, $0CB3 -- byte forced by reducing MMUMode to 
MMU32bit might be usefull, though I'm not quite sure how.

Later,

 /---------------------------------------------------------------------\
|David A. Gatwood             And Richard Cory, one calm summer night,  |
|davagatw@mars              Went home and put a bullet through his head.|
|dgatwood@nyx.cs.du.edu              --Edwin Arlington Robinson         |
|http://mars.utm.edu/~davagatw -or- http://nox.cs.du.edu:8001/~dgatwood |
 \---------------------------------------------------------------------/