Path: utzoo!attcan!uunet!lll-winken!ames!pasteur!ucbvax!bloom-beacon!think!ephraim
From: ephraim@think.COM (Ephraim Vishniac)
Newsgroups: comp.sys.mac
Subject: Re: Virtual Memory INIT
Message-ID: <35420@think.UUCP>
Date: 16 Jan 89 14:04:08 GMT
References: <8901151644.AA17944@Portia.stanford.edu>
Sender: news@think.UUCP
Reply-To: ephraim@vidar.think.com.UUCP (Ephraim Vishniac)
Organization: Thinking Machines Corporation, Cambridge MA, USA
Lines: 14

In article <8901151644.AA17944@Portia.stanford.edu> name@PORTIA.STANFORD.EDU (tony cooper) writes:
>According to my calculations 2^24 is 16 Megabytes. So why is the virtual
>memory INIT limited to just 8Mb? Then the next question is: Why stop at
>2^24? Why can't the virtual memory be as big as the disk?

Mostly because the Mac OS isn't 32-bit yet.  In the 24-bit addressing
version, it needs space for things other than user memory.  The ROM is
mapped at 8M, and above the ROM is I/O space and slot space.  

Ephraim Vishniac					  ephraim@think.com
Thinking Machines Corporation / 245 First Street / Cambridge, MA 02142-1214

	"Arlo Guthrie, it seems, has found what he was looking for:
		God, and the Macintosh." (Boston Globe)