Path: g2news1.google.com!news3.google.com!feeder1-2.proxad.net!proxad.net!feeder2-2.proxad.net!news.clara.net!wagner.news.clara.net!zen.net.uk!hamilton.zen.co.uk!feed4.jnfs.ja.net!jnfs.ja.net!gemini.csx.cam.ac.uk!news.cam.ac.uk!not-for-mail From: n...@cam.ac.uk Newsgroups: comp.lang.fortran Subject: Re: how to declare doubles in f95 Date: Thu, 29 Jan 2009 18:58:43 +0000 (GMT) Organization: University of Cambridge Lines: 45 Message-ID: References: <0b898c8f-5866-4942-bf2b-171655d6658a@r15g2000prh.googlegroups.com> NNTP-Posting-Host: soup.linux.pwf.cam.ac.uk In article , Ron Shepard wrote: > >> "Many"? And "common"? Not really. The only ones that I can think >> of were CDCs and Crays, all of which were extremely specialised >> supercomputers that sold in very small numbers. What else were you >> thinking of? > >There were also the fortran programmable attached processors that were >fairly common in the 80's. These included the FPS-164 and FPS-264 >machines which I used. Certainly if you count every computational >scientist and engineer who used a CDC, Cray, ETA, SCS, or one of these >attached processors in the 80's, you would get a high percentage, >probably over 90% of us. Not only were these machines sold to >individual groups and local departments, but there was also a number of >national supercomputer centers (NSF, DOE, DoD) which gave access to >almost everyone who applied. If that >90% estimate is correct, then >"common" would be the correct description, right? My feeling is that >scientists in the UK (your address) had wide access to these kinds of >machines earlier than they did here in the US. 90% of who? Most of the coprocessor compilers I saw took a 'conventional' view of precision, but I didn't see many as those coprocessors never really took off. >> Ones using 48 bits for single and 96 for double were probably more >> common. Once upon a time .... > >On the other hand, I don't know anyone who used a machine like this. I >think Harris computers used 3-byte and 6-byte data, which is almost what >you are claiming, but I think there were fewer of these machines than >the types described above, and they were almost certainly less commonly >used. There were no national supercomputer centers based on Harris >computers, for example. I personally never used one, but I exchanged >code with collaborators who did, and wrestled with their integer*3 and >real*6 declarations. The ICL 1900 range was perhaps the main one, but nowhere near the only one. I think it took that word size from Ferranti. Regards, Nick Maclaren.