Path: csiph.com!x330-a1.tempe.blueboxinc.net!aioe.org!selfless.tophat.at!fu-berlin.de!uni-berlin.de!individual.net!not-for-mail From: vandys@vsta.org Newsgroups: comp.os.vms,alt.sys.pdp11,comp.sys.dec,vmsnet.pdp-11 Subject: Re: Y3K for PDP-11 Operating Systems Date: 9 May 2011 23:05:55 GMT Lines: 24 Message-ID: <92raajFe87U1@mid.individual.net> References: <4d99c3b6$0$23756$14726298@news.sunsite.dk> <4dc032d4$0$313$14726298@news.sunsite.dk> <7d287cc3-4605-49a0-826e-fb92fc14e98d@j28g2000vbp.googlegroups.com> <92bjl8F19sU1@mid.individual.net> <92d114Fhm7U1@mid.individual.net> <92ddfkF764U1@mid.individual.net> <4DC4390F.9040401@eisner.decus.org> <92r5ntFf3hU1@mid.individual.net> X-Trace: individual.net VGulf1NubdslQyVYwrNQOwxTrH9DAlQpoUikWM+RaKpud87evV X-Orig-Path: not-for-mail Cancel-Lock: sha1:ej31GJUkIa2lhoz0zyfWnrtMPsU= User-Agent: tin/1.8.3-20070201 ("Scotasay") (UNIX) (Linux/2.6.32-31-generic-pae (i686)) Xref: x330-a1.tempe.blueboxinc.net comp.os.vms:2739 comp.sys.dec:424 In alt.sys.pdp11 Johnny Billquist wrote: > I wouldn't be so sure on string handling, since the VAX have lots of > native instructions to deal with that, which the 11/70 do not. Integer > on the other hand, yes. I think it was most competetive when you used multiple of its more optimized instructions. For instance, my recollection is that the single-instruction bulk string ops ran slower than the hand coded move/loop constructs. (Most of my time was on 750's and the odd 780, and this no doubt changed as DEC fleshed out their Vax line.) > The VAX have a single instruction for that, while the > PDP-11 needs to manually handle both processor registers and MMU > registers. Having a single instruction does not mean you have a *fast* single instruction. That was definitely the case for bulk string ops. I don't recall actual task switch performance; that was not an area which caused me problems. -- Andy Valencia Home page: http://www.vsta.org/andy/ To contact me: http://www.vsta.org/contact/andy.html