From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Thread: 103376,6192a34d0c9ffe5b X-Google-NewGroupId: yes X-Google-Attributes: gida07f3367d7,domainid0,public,usenet X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news2.google.com!news4.google.com!feeder.news-service.com!news.netcologne.de!newsfeed-fusi2.netcologne.de!feeder.erje.net!news.albasani.net!.POSTED!not-for-mail From: "Frank J. Lhota" Newsgroups: comp.lang.ada Subject: Re: Ada Tutor Web Site Shutting Down Date: Fri, 13 May 2011 13:22:41 -0400 Organization: albasani.net Message-ID: References: <7f53de8e-2400-4c87-a818-0b389e117c42@e21g2000yqe.googlegroups.com> <4d9eea12$0$302$14726298@news.sunsite.dk> <2aeab5d1-fa6d-47de-ab53-9a8e6ab5f27a@h9g2000pre.googlegroups.com> <3a6f1fc2-3ae0-42d9-b483-d16cf7ab1566@x8g2000prh.googlegroups.com> <991499fb-bc24-4d7e-baf6-a9c0e16333e6@k22g2000yqh.googlegroups.com> <291504a4-ec55-45f1-bf7f-13078bf71c3e@m10g2000yqd.googlegroups.com> <4dcbf260$0$6992$9b4e6d93@newsspool4.arcor-online.net> Reply-To: FrankLho.NOSPAM@rcn.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Trace: news.albasani.net fBBYR1Sct4jj5iL9ABGTzkNP6hAtYmsYoxvGzkRAUtgWwWVogEZA0AUlXdjQUXWWY2BjoD3krlTOvkojWR2+13LWaySmuS3R4mROwJHBCsrpAntp6ksGT9lfmjJprRPa NNTP-Posting-Date: Fri, 13 May 2011 17:22:45 +0000 (UTC) Injection-Info: news.albasani.net; logging-data="XUDCxb7/GZMtiatM35rZRXi4a0K1B7bwJiyt21S2ryfjijUujo8z2pKgcWPowKskAQ/Edeaefn5DINXsJ+w5EHxrdAQeJVA800c/WA7EaFZV1qIWNr+qvx9xPvcDxbol"; mail-complaints-to="abuse@albasani.net" User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.2.17) Gecko/20110414 Lightning/1.0b2 Thunderbird/3.1.10 In-Reply-To: Cancel-Lock: sha1:5Kw+8xcDtHczgSjjNoTw3X5e0fM= Xref: g2news2.google.com comp.lang.ada:20223 Date: 2011-05-13T13:22:41-04:00 List-Id: On 5/13/2011 12:19 PM, Paul Colin Gloster wrote: > Rugxulo sent on May 12th, 2011: > |--------------------------------------------------------------------------| > |"[..] | > | | > |DOS was used because of the extremely low RAM of the day (16 to 64 kb, | > |I think) on the original IBM PC. [..] | > |[..] | > | | > |[..]" | > |--------------------------------------------------------------------------| > > All IBM PCs had much more RAM than 64 kilobytes. A Commodore 64 had 64 > kilobytes and cost circa 10% as much as an IBM PC. Some Sinclair ZX81s > and Sinclair ZX Spectrums (also branded as Timex instead of Sinclair) > had 16 kilobytes of RAM and cost circa 1% and circa 3% as much as an > IBM PC, respectively. IBM PCs did have more than 64 KB, but they still suffered from severe memory limits. Memory provides an excellent example of Moore's law: in the 1980's, memory was an order of magnitude more expensive than it is now. Some PC's were equipped with as little as 256 KB low memory (that is, memory for the OS and applications). Granted, many early mainframes had even tighter memory constraints, but many of these platforms could alleviate the memory shortage somewhat by using temporary disk space. The first PC's could not take this approach because disk space was even more limited than memory. The first PCs had no hard disk. Instead, they used low-density single-sided 5 1/4" floppies with a capacity of 180 KB. MS-DOS has a lot of annoying limitations. But it is hard to imagine anyone doing something much better given the constraints of the platform that DOS was designed for. -- "All things extant in this world, Gods of Heaven, gods of Earth, Let everything be as it should be; Thus shall it be!" - Magical chant from "Magical Shopping Arcade Abenobashi" "Drizzle, Drazzle, Drozzle, Drome, Time for this one to come home!" - Mr. Wizard from "Tooter Turtle"