Path: utzoo!attcan!uunet!mcsun!ukc!stl!tom From: tom@stl.stc.co.uk (Tom Thomson) Newsgroups: comp.arch Subject: Re: Porting OSes (was DEC RISC Architecture) Message-ID: <3607@stl.stc.co.uk> Date: 16 Oct 90 14:37:55 GMT References: <4462@trantor.harris-atd.com> <107038@convex.convex.com> <15007@hydra.gatech.EDU> <10734@pt.cs.cmu.edu> Sender: news@stl.stc.co.uk Reply-To: "Tom Thomson" Organization: STC Technology Limited, London Road, Harlow, Essex, UK Lines: 15 In article <10734@pt.cs.cmu.edu> lindsay@gandalf.cs.cmu.edu (Donald Lindsay) writes: >The whole idea of porting an OS was new in the mid-70's: most of us Not really new. Lots of people had thought about it as part of thinking about introducing a new machine. ICL had not only thought about it, but done it before the mid 70s: old operating systems from the 1900 series were on 2903 (24 bit mainframe os ported to 32 bit mini with 2 instruction streams, null slots after branches, main store requests 3 slots before main store access...) and in the early 70s in Edinburgh my team ran VME/K (2900 mainframe os) and the 5J and Multimac OSs{from S4} in prototype form on 2903 too. The S4 and 1900 OSs were run on 2900 mainframes from mid 70s onwards (and accounted in the early days for far more of the company's revenue than the OSs designed for 2900 mainframes). So porting OSs was sufficiently old hat to be hard commercial business by the mid 70s, not a new idea. Tom[tom%uk03.icl.icl.gold-400.gb@ukc.ac.uk/tom@nw.stl.stc.co.uk/tom@prg.ox.ac.uk