Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 (Tek) 9/28/84 based on 9/17/84; site mako.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!mhuxn!mhuxj!mhuxr!ulysses!allegra!mit-eddie!genrad!decvax!tektronix!orca!mako!jans From: jans@mako.UUCP (Jan Steinman) Newsgroups: net.micro.68k Subject: Re: 32 vs. 24 Bit Addresses Message-ID: <608@mako.UUCP> Date: Thu, 28-Feb-85 17:35:38 EST Article-I.D.: mako.608 Posted: Thu Feb 28 17:35:38 1985 Date-Received: Mon, 4-Mar-85 04:37:55 EST References: <342@oakhill.UUCP> Reply-To: jans@mako.UUCP (Jan Steinman) Organization: Tektronix, Wilsonville OR Lines: 12 Summary: In article <342@oakhill.UUCP> cruess@oakhill.UUCP (Michael Cruess) writes: >As an aside, having 32 bit addresses designed into the M68000 Family from >the beginning has made the instruction set upgrade in the MC68020 easy... I know of a 68010 software project that DEPENDS on those bits being masked off chip. It uses the eight most significant bits of pointers to objects as flags that contain information obout those objects. Of course, if a usable Motorola MMU is available when they port to the 68020, they can simply fold that huge address space over... -- :::::: Jan Steinman Box 1000, MS 61-161 (w)503/685-2843 :::::: :::::: tektronix!tekecs!jans Wilsonville, OR 97070 (h)503/657-7703 ::::::