Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site unisoft.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!mit-eddie!godot!harvard!seismo!hao!hplabs!pesnta!amd!dual!unisoft!pc From: pc@unisoft.UUCP (Paul Campbell) Newsgroups: net.lang.pascal,net.lang.c Subject: Re: Re: opt cmplrs vs. opt prgrmrs (really coding VMS in assembler) Message-ID: <392@unisoft.UUCP> Date: Thu, 17-Jan-85 11:11:40 EST Article-I.D.: unisoft.392 Posted: Thu Jan 17 11:11:40 1985 Date-Received: Mon, 21-Jan-85 04:36:36 EST References: <285@harvard.ARPA>, <4922@utzoo.UUCP> Organization: UniSoft Corp., Berkeley Lines: 14 Xref: watmath net.lang.pascal:205 net.lang.c:3984 (...) I heard a different story .... they coded the VMS kernel in assembler because they didn't have a Vax .... (VMS was designed on a simulator running on a pair of 11-70s) they built the hardware alongside the operating system and tuned the instruction set as they wrote the operating system. The context switch instructions were only decided on once the new what contexts VMS would need to switch. Most of the compilers available for VMS on the day the Vax was released were written in compatability mode and came straight from RSX. Paul Campbell ucbvax!unisoft!pc