Article View: comp.arch
Article #11457Re: Can old architectures run fast?
From: C.E. Thompson
Date: Thu, 09 May 1991 21:49
Date: Thu, 09 May 1991 21:49
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In article <1991May05.174756.9026@iecc.cambridge.ma.us> johnl@iecc.cambridge.ma.us (John R. Levine) writes: > ... w.r.t. the IBM 360 architecture ... >(Yes, it also had things like edit-and-mark which is a disaster in a paging >system, they weren't totally prescient.) > EDMK was an implementation problem on early IBM 370s with virtual memory, because the length of the area to be modified could only be determined by trial execution, while address translation exceptions were required to nullify all side-effects of the instruction. But this isn't a problem in modern implementations (e.g. IBM 308x and 3090) which have general mechanisms for rolling back the logical state of of a CPU, including recent storage modifications. Chris Thompson JANET: cet1@uk.ac.cam.phx Internet: cet1%phx.cam.ac.uk@nsfnet-relay.ac.uk
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Path: arc1-ca.pugleaf.net!utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!uunet!mcsun!ukc!cam-cl!news From: cet1@cl.cam.ac.uk (C.E. Thompson) Newsgroups: comp.arch Subject: Re: Can old architectures run fast? Message-ID: <1991May9.214959.22599@cl.cam.ac.uk> Date: 9 May 91 21:49:59 GMT References: <8283@uceng.UC.EDU> <7628@auspex.auspex.com> <8324@uceng.UC.EDU> <1991May05.174756.9026@iecc.cambridge.ma.us> Reply-To: cet1@cl.cam.ac.uk (C.E. Thompson) Organization: U of Cambridge Comp Lab, UK Lines: 16