Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10 5/3/83; site utzoo.UUCP Path: utzoo!henry From: henry@utzoo.UUCP (Henry Spencer) Newsgroups: net.micro.68k,net.micro.16k Subject: Re: Re: PDP11s vs the micros Message-ID: <5874@utzoo.UUCP> Date: Wed, 14-Aug-85 13:07:57 EDT Article-I.D.: utzoo.5874 Posted: Wed Aug 14 13:07:57 1985 Date-Received: Wed, 14-Aug-85 13:07:57 EDT References: <1617@hao.UUCP> <847@mako.UUCP> <2422@sun.uucp>, <2607@sun.uucp> Organization: U of Toronto Zoology Lines: 16 > > Any particular reason to do this rather than restart the instruction from > > where it left off? > > Less internal state to dump? (Which means less microcode/whatever to do the > dumping and restoring, and less code in the kernel to check that the state, > if accessible to the user, hasn't been tampered with.) Motorola obviously :-) views its 68020 line primarily as a way to sell memory chips. Between the incredible pile of trash it heaves onto the stack when you take a page fault, and the huge internal state of the 68881 FPU that has to be shoveled in and out every time you context-switch (what's the betting Motorola's next FPU chip has DMA? :-), the memory market is clearly what they're aiming at. That and the cache market. -- Henry Spencer @ U of Toronto Zoology {allegra,ihnp4,linus,decvax}!utzoo!henry