Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: Notesfiles $Revision: 1.7.0.10 $; site uicsl Path: utzoo!linus!philabs!cmcl2!seismo!caip!topaz!packard!hoxna!houxm!ihnp4!inuxc!pur-ee!uiucdcs!uicsl!hr From: hr@uicsl.UUCP Newsgroups: net.micro.amiga Subject: Re: Amiga MMU question Message-ID: <151400006@uicsl> Date: Thu, 7-Nov-85 10:50:00 EST Article-I.D.: uicsl.151400006 Posted: Thu Nov 7 10:50:00 1985 Date-Received: Sun, 10-Nov-85 03:40:25 EST References: <192@ucdavis.UUCP> Lines: 29 Nf-ID: #R:ucdavis.UUCP:-19200:uicsl:151400006:000:1155 Nf-From: uicsl.UUCP!hr Nov 7 09:50:00 1985 RE: "> Multitasking does NOT require an MMU. Processes are allocated separate > places in memory, and then are timesliced..." Actually, I have seen a TIMESHARING system that didn't have an MMU. A couple of groups here had Alpha Micro systems. The processor was the Western Digital "almost an LSI-11" chip set. The operating system looked to the user a LOT like DEC's TOPS-10. PPN [1,2] was the system account, for instance. All the high level languages, like Lisp, generated position independent code. They also checked to make sure that the users didn't get outside of their areas. If you wrote in assembler, you could do nasty things. Since most of the users were doing word processing or simple programs, and were friendly, the system seemed fairly stable. A question for those who know. How much would a simple MMU have cost to implement? Stride sells one for either $400 or $600 (I can't remember). The Amiga was obviously designed to meet a specific price point. Why else would they have made the 256KB an option? Our local dealer has apparently not sold a single 256KB only system. harold ravlin {ihnp4,pur-ee}!uiucdcs!uicsl!hr