Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!pacific.mps.ohio-state.edu!linac!unixhub!stanford.edu!neon.Stanford.EDU!torrie From: torrie@cs.stanford.edu (Evan Torrie) Newsgroups: comp.sys.amiga.advocacy Subject: Re: 8-bit death Message-ID: <1991May10.183627.29486@neon.Stanford.EDU> Date: 10 May 91 18:36:27 GMT References: <2945.tnews@templar.actrix.gen.nz> <3474.tnews@templar.actrix.gen.nz> <1991May9.191412.15264@midway.uchicago.edu> <3515.tnews@templar.actrix.gen.nz> Sender: torrie@neon.Stanford.EDU (Evan James Torrie) Organization: Computer Science Department, Stanford University, Ca , USA Lines: 29 jbickers@templar.actrix.gen.nz (John Bickers) writes: >Quoted from <1991May9.191412.15264@midway.uchicago.edu> by jcav@quads.uchicago.edu (john cavallino): >> As I understand it, the TRAPn instructions were specifically intended by >> Motorola to be used to invoke the operating system. After all, there are > Perhaps they were thinking of dishwasher OSes, or something. Trying > to compete with Intel for the dishwasher OS market... :) If I recall correctly, isn't this how Unix handles system entry calls? My recollection of PDP-11 V7 Unix was that all system calls were invoked via a trap instruction, with a word afterwords encoding which call was desired. >> operating system, which uses the MC680x0 A-line unimplemented instructions >> as the OS interface, with the routine index and various flags encoded into >> the instruction word. > Well, the ST thing has desensitized me, otherwise I'd fall over > backwards laughing at this one. I guess this is well hidden by Mac > C compilers etc. Like I say, isn't this how Unix does it? -- ------------------------------------------------------------------------------ Evan Torrie. Stanford University, Class of 199? torrie@cs.stanford.edu Murphy's Law of Intelism: Just when you thought Intel had done everything possible to pervert the course of computer architecture, they bring out the 860