Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!uwm.edu!linac!mp.cs.niu.edu!ux1.cso.uiuc.edu!uxa.cso.uiuc.edu!ml27192
From: ml27192@uxa.cso.uiuc.edu (Mark Lanett)
Newsgroups: comp.sys.mac.system
Subject: Re: Virtual Memory problem
Message-ID: <1991May19.042323.20895@ux1.cso.uiuc.edu>
Date: 19 May 91 04:23:23 GMT
References: <29368@hydra.gatech.EDU> <13704@pasteur.Berkeley.EDU>
Sender: usenet@ux1.cso.uiuc.edu (News)
Organization: University of Illinois at Urbana
Lines: 43

news@pasteur.Berkeley.EDU (Six o'clock News) writes:

>From: chenp@cory.Berkeley.EDU (Paul "Mega Drive and Lynx" Chen)
>Path: cory.Berkeley.EDU!chenp

>>Hi, I work on an original Mac II with a 68020 processor and PMMU installed.
>>It has 8 megs of RAM on board but when I pull up the memory control panel,
>>it only allows me to access 12 megs of RAM as virtual memory. Does anybody
>>have a clue as to why it won't let me access at least 16 megs if not more?
>>Thanks for your help.

>Hmm, interesting. All I know is that only 32-bit clean ROM's can access the
>full 32 bits of address. Every other Mac has 32-bit dirty (?) ROM's so they
>work in 24-bit mode, which means you can only access up to 16 megs of VM.
>The only 32-bit clean ROM Macs that I know of are the ci, fx, and I think the
>si.

>As for your other problem, I don't know.

That's 16 megs minus 1 meg per NuBus slot used minus some other stuff. With
two cards on board 12 megs is the result.

>Paul


>-------------------------------------------------------------------------------
>"... Particle man			
> Is he a dot, or is he a speck?		      	Game Boy
> When he's underwater				Lynx
> does he get wet?				Mega Drive
> or does the water get him instead?"		PC-Engine CG
>(Some mind-boggling questions from the song
> "Particle Man" by They Might Be Giants.)
>-------------------------------------------------------------------------------
>  chenp@cory.berkeley.edu			One of these days I'll get my
>						hands on System 7.
>-------------------------------------------------------------------------------
--
//-----------------------------------------------------------------------------
Mark Lanett						ml27192@uxa.cs.uiuc.edu
Software Tools Group, NCSA				mlanett@ncsa.uiuc.edu
To create a Mac emulator you would only need to write a screensaver for Windows
that draws a bomb box.