Path: csiph.com!x330-a1.tempe.blueboxinc.net!usenet.pasdenom.info!aioe.org!news.mixmin.net!newsreader4.netcologne.de!news.netcologne.de!news.tele.dk!feed118.news.tele.dk!dotsrc.org!filter.dotsrc.org!news.dotsrc.org!not-for-mail Date: Thu, 21 Jul 2011 16:40:08 -0400 From: =?UTF-8?B?QXJuZSBWYWpow7hq?= User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:5.0) Gecko/20110624 Thunderbird/5.0 MIME-Version: 1.0 Newsgroups: comp.lang.java.programmer Subject: Re: Arithmetic overflow checking References: <015aeb15-57db-48ab-9cd4-77f8448b632f@w24g2000yqw.googlegroups.com> <2rydnez7l-H5BYnTnZ2dnUVZ_vGdnZ2d@earthlink.com> <9LWdnZH2hdfmyYvTnZ2dnUVZ_vidnZ2d@posted.palinacquisition> <1K2dnVVEK60FcoTTnZ2dnUVZ_hKdnZ2d@earthlink.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Lines: 66 Message-ID: <4e288eaa$0$316$14726298@news.sunsite.dk> Organization: SunSITE.dk - Supporting Open source NNTP-Posting-Host: 72.192.23.157 X-Trace: news.sunsite.dk DXC=ALCOofa^_DX07[Q;R2I\gZi?IYef1ekjYXb4T X-Complaints-To: staff@sunsite.dk Xref: x330-a1.tempe.blueboxinc.net comp.lang.java.programmer:6349 On 7/10/2011 3:22 PM, Martin Gregorie wrote: > On Sun, 10 Jul 2011 11:29:39 -0700, Patricia Shanahan wrote: > >> On 7/10/2011 11:07 AM, Martin Gregorie wrote: >>> On Sun, 10 Jul 2011 10:53:09 -0400, David Lamb wrote: >>> >>>> On 08/07/2011 12:30 AM, Eric Sosman wrote: >>>>> On 7/7/2011 8:51 PM, Peter Duniho wrote: >>>>>> [...] >>>>>> I would not worry about the "simple" or "efficient" criteria. IMHO, >>>>>> if one is deciding to apply overflow checking to every computation, >>>>>> one has already abandoned the hope of efficiency. >>>>> >>>>> I've used machines that raised overflow traps "for free," >>>> ... >>>>> (The machines I speak of were from forty-odd years ago >>>> >>>> When microprocessors started to arrive on the scene, a lot of >>>> old-timey hardware folks said they'd forgotten 30+ years of hardware >>>> design. When operating systems for computers based on said processors >>>> came out, a lot of old-timey software folks said they'd forgotten 30+ >>>> years of operating system design. We seem to still be suffering the >>>> consequences. >>> >>> That happened not once, but twice. >>> >>> The first great leap backward was the minicomputer era, when the likes >>> of the PDP-8 arrived with a single user, single tasking OS reminiscent >>> of early computers, except they generally had teletypes instead of >>> banks of switches and flashing lights. By then the better mainframes >>> were multi- user, multitasking beasts. >>> >>> Then the first microcomputers arrived in the mid/late '70s. By this >>> time the better minis had multi-tasking operating systems, but micros >>> had re- implemented the earliest mini OSes - CP/M was near as dammit a >>> copy of the old PDP-8 OS (RSTS?) from the late 60s - and the earliest >>> micros even had switches and flashing lights (KIM-1, IMSAI 8080). By >>> 1980 the minis were running UNIX but the latest and greatest micros had >>> - drumroll - MS- DOS! >>> >>> >>> >> Only twice? Aren't you forgetting "smart" phones. One of the great >> advances in Android is (Drum roll!) multitasking!!! >> > They don't count since, unlike minis and micros, their builders didn't > retreat to the techno-stone age, ignore progress made to date, and build > primitive OS by rubbing (metaphorical) sticks together. > > AFAIK all smartphones started an a more advanced level because they > inherited better operating systems. IIRC these all originated on > electronic memo pads such as Psion, HP and Palm Pilot made, and were all > a lot more advanced than the likes of RSTS, CP/M, Flex09, etc. Leastwise, > I don't think you can consider Symbian and whatever MS was calling the > iPAQ OS at that stage any more primitive than the contemporary versions > of MacOS, OS/2 or even Windows, though admittedly they were rather behind > UNIX and its distant relations such as OS-9/68K. If they don't support multi-tasking I would say that they in at least one aspect is behind the desktop OS'es. (how important multitasking is on a smartphone is a different discussion) Arne