Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site unc.unc.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!mcnc!unc!omondi From: omondi@unc.UUCP (Amos Omondi) Newsgroups: net.arch Subject: Re: Why Virtual Memory Message-ID: <405@unc.unc.UUCP> Date: Sat, 26-Oct-85 20:47:13 EST Article-I.D.: unc.405 Posted: Sat Oct 26 20:47:13 1985 Date-Received: Mon, 28-Oct-85 03:29:27 EST References: <480@seismo.CSS.GOV> <384@unc.unc.UUCP> Organization: CS Dept, U. of N. Carolina, Chapel Hill Lines: 21 > > It is interesting to note that 10 years ago or so, all large systems > had virtual memory whereas small systems did not. > > Now the largest systems (e.g., Cray 2) do not have virtual memory, > whereas it is more and more common for small systems ("microprocessors", > and I use the term in quotes) to have virtual memory. > > I wonder if in another ten years the "small" systems won't have > virtual memory, but the "large" (i.e., gigantic) systems will again? > > The "wheel of reincarnation" turns .... > In taking the Cray 2 as an example, one should take historical, philosophical , etc. considerations into account. The CDC 6600, CDC 7600, CRAY 1, and CRAY 2 do not have virtual memory; and Seymour Cray was largely responsible for their designs. Other CDC machines, inculding the Cyber 200 series which are the in Cray1-Cray2 perfomance range, have virtual memory as do several of the new Japanese supercomputers .