Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!olivea!mintaka!mintaka.lcs.mit.edu!burley From: burley@geech.ai.mit.edu (Craig Burley) Newsgroups: comp.arch Subject: Re: Be Prepared... Message-ID: Date: 14 Feb 91 23:38:32 GMT References: <1991Feb13.160718.25759@visix.com> Sender: daemon@mintaka.lcs.mit.edu (Lucifer Maleficius) Organization: Free Software Foundation 545 Tech Square Cambridge, MA 02139 (617) 253-8568 Lines: 27 In-Reply-To: wolfe@vw.ece.cmu.edu's message of 14 Feb 91 15:48:18 GMT In article wolfe@vw.ece.cmu.edu (Andrew Wolfe) writes: I have been told that it is estimated that 64-bits will address all of the subatomic particles in our universe. Not exactly; 64 bits might be enough to assign each subatomic particle in our universe a distinct address, but that isn't quite the same thing as actually addressing them... :-) (Hmm, it would give new meaning to the phrase "pointer to string", wouldn't it?) Even so, clearly 64 bits will not be enough. I mean, who wants to commit to a new architecture that can represent only ONE universe at a time? Sheesh, the last thing we need is for somebody to tack a virtual universe segment descriptor onto the 64-bit address and make a 96-bit disjoint address space or some such thing. :-) More seriously, one of the uses for pointers is to have them fly around on a network and have enough information to identify target node and address within the node. In systems like this, even 64 bits might not be enough when they get enough nodes (with enough memory) on them. 96 bits, on the other hand, might well be enough for the next 25-50 years or more. Though I'm not sure whether anyone has shown that systems built out of distinct processors that intercommunicate using pointers into each others' address spaces is a better approach than other, less architecturally demanding, approaches. -- James Craig Burley, Software Craftsperson burley@ai.mit.edu