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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,76da32d8c4934801 X-Google-Attributes: gid103376,public From: stt@houdini.camb.inmet.com (Tucker Taft) Subject: Re: Operating System in Ada (was Ada --> C Translation) Date: 1998/10/13 Message-ID: #1/1 X-Deja-AN: 400459254 Sender: news@inmet.camb.inmet.com (USENET news) X-Nntp-Posting-Host: houdini.camb.inmet.com References: <36222b68.725864@SantaClara01.news.InterNex.Net> Organization: Intermetrics, Inc. Newsgroups: comp.lang.ada Date: 1998-10-13T00:00:00+00:00 List-Id: Tom Moran (tmoran@bix.com) wrote: : What constitutes an Operating System? An embedded kernel? Does the : Patriot missile have an OS? If so, is it written in Ada? Yes, and yes. (Actually, I don't know anything about the missiles per se. I know about the Patriot ground support system, which is the one that does all the hard work of tracking incoming missiles and choosing where and when to fire. That was written in Jovial, but has now been rewritten in Ada 95.) : ... If so, does that count? There are plenty of real-time executives written in Ada (perhaps too many ;-). Also, essentially every Ada run-time kernel is written in Ada, and it has a number of operating-system-like functions. The big pain in building your own commercial operating system is keeping up with all the quirks of the hardware which keep evolving, like virtual memory systems, serial devices, timers, interrupt controllers, network interfaces, graphics subsystems, disk drives, etc., etc., etc. Even if the Instruction Set Architecture (ISA) is relatively stable, nothing else is, in the hardware world. -- -Tucker Taft stt@inmet.com http://www.inmet.com/~stt/ Intermetrics, Inc. Burlington, MA USA An AverStar Company