Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uwm.edu!genbank!ames!haven!grebyn!ckp
From: ckp@grebyn.com (Checkpoint Technologies)
Newsgroups: comp.sys.amiga
Subject: Re: Commodore New Products/Price Reductions COMDEX Announcements
Message-ID: <14061@grebyn.com>
Date: 1 Dec 89 02:54:15 GMT
References: <787@crash.cts.com> <1989Nov30.172032.23894@aucs.uucp>
Reply-To: ckp@grebyn.UUCP (Checkpoint Technologies)
Organization: Grebyn Timesharing, Vienna, VA, USA
Lines: 17

In article <1989Nov30.172032.23894@aucs.uucp> 840445m@aucs.UUCP (Alan McKay) writes:
>In article <787@crash.cts.com> lgreen@pnet01.cts.com (Lawrence Greenwald) writes:
>>68030  =  68020 CPU + BUILTIN 68851 MMU!!!
>>
>>Adding another '851 is a waste of silicon and board space!!
>>
>
>68030 = 68020 + SPEED + A SUBSET OF THE 68851 MMU
>					 ^^^^^^
>
	Don't worry, there's nothing the 68030 is lacking that's worth
it. The 68851 contains a *lot* of features for an MMU. There's nothing
of real importance missing from the 68030. Just the breakpoint registers
(not nearly as useful as you might think), and the 7 level memory
protection scheme that's only useful when you're using the CALLM
and RETM instructions. And in fact, CALLM and RETM aren't that
useful either. So guess what - the 68030 left them out.