Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!munnari.oz.au!comp.vuw.ac.nz!gp.govt.nz!zl2tnm!don From: don@zl2tnm.gp.govt.nz (Don Stokes) Newsgroups: comp.sys.dec Subject: Re: MicroVax hardware compatibility Message-ID: Date: 24 Aug 90 11:05:19 GMT References: <12927@hydra.gatech.EDU> Organization: Me? Organised? Lines: 23 bb16@prism.gatech.EDU (Scott Bostater) writes: > I hope this doesn't sound too naive, but.... > > I have some software written for VMS version 4.6 that makes use of a PDP-11 > backward compatibility mode. I want to run the software on a microvax. Is > this backward compatibility mode going to shoot me in the foot? Well, it depends how you define "shoot yourself in the foot". If you mean "will it work?", the answer is yes (you may need to purchase VAX RSX; I'm not certain offhand if the emulation software is provided in VMS or in the RSX kit). Note I say "emulation" -- only VAX11/7xx and VAX86xx machines have compatibility mode in hardware; others do it in software. In short, if you are using the PDP-11 compatibility mode instructions extensively in compute intensive processing, you may suffer a serious performance hit. Otherwise, you might just get away with it. Don Stokes, ZL2TNM / / Home: don@zl2tnm.gp.govt.nz Systems Programmer /GP/ Government Printing Office Work: don@gp.govt.nz __________________/ /__Wellington, New Zealand_____or:_PSI%(5301)47000028::DON