Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!samsung!zaphod.mps.ohio-state.edu!mips!apple!amdahl!littauer From: littauer@uts.amdahl.com (Tom Littauer) Newsgroups: comp.arch Subject: Re: 64-bit addresses Summary: A few words on 360/370/XA/ESA Message-ID: Date: 3 Mar 90 02:28:00 GMT References: <1786@gannet.cl.cam.ac.uk> <1990Mar2.232735.6071@world.std.com> Reply-To: littauer@amdahl.uts.amdahl.com (Tom Littauer) Organization: Amdahl Corporation, Sunnyvale CA Lines: 42 In article <1990Mar2.232735.6071@world.std.com> bzs@world.std.com (Barry Shein) writes: > > ... a good summary of 370 architecture history, but there're a few nits... > >At that point of course they're out of juice, and about all one can do >is what was described, use any more memory as a fast place to store >things while they're not in use rather than going to disk. I wonder >why they didn't re-invent the separate I&D space of the PDP-11? Well, they did. In the *NEW* architecture, ESA, they've added an addressing mode which allows one instruction to work in two address spaces at the same time, while living in a third. I forget the absolute limit on the number of address spaces that can be so used, but it's over 4K. The buzzname for this is Hiperspaces (probably TM IBM). >The major economic advantage is not having to move to a non-370 >architecture. ... and a non-trivial one, as you point out. > It probably still is a cost-effective database >transaction machine for very large databases and other similar >data-intensive tasks. It is indeed, especially if you use UNIX (definitely TM AT&T) as the operating system. Double especially if you can run the older proprietary stuff at the same time on the same machine. >So, there's reasons to keep kicking that dead whale down the beach. >-- > -Barry Shein Thank you for your support :-) Tom Littauer -- UUCP: littauer@amdahl.amdahl.com or: {sun,decwrl,hplabs,pyramid,ames,uunet}!amdahl!littauer DDD: (408) 737-5056 USPS: Amdahl Corp. M/S 278, 1250 E. Arques Av, Sunnyvale, CA 94086 I'll tell you when I'm giving you the party line. The rest of the time it's my very own ravings (accept no substitutes).