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=-1.9 required=5.0 tests=BAYES_00 autolearn=ham autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,55958fd991db66fe X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2002-08-30 16:56:32 PST Path: archiver1.google.com!postnews1.google.com!not-for-mail From: sam@rfc1149.net (Samuel Tardieu) Newsgroups: comp.lang.ada Subject: Re: Ada-inspired OS/Language Date: 30 Aug 2002 16:56:32 -0700 Organization: http://groups.google.com/ Message-ID: References: <3D628304.3040506@cogeco.ca> NNTP-Posting-Host: 212.198.0.96 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: posting.google.com 1030751792 25413 127.0.0.1 (30 Aug 2002 23:56:32 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: 30 Aug 2002 23:56:32 GMT Xref: archiver1.google.com comp.lang.ada:28614 Date: 2002-08-30T23:56:32+00:00 List-Id: "Warren W. Gay VE3WWG" wrote in message news:<3D628304.3040506@cogeco.ca>... > Now we've regressed with the palms etc., back to this no-protection model. Are you referring to Palm Inc. handhelds? (if you aren't, let's blame the language barrier and ignore the rest of this message :-). If this is the case, this is unfair to Palm Inc. Their handheld devices contain a chip which prevents memory writes outside of the heap (only one application can be running and thus access the heap at a given time, and the stack is located in the heap space). When an application wants to write into a so-called database (for example another application or users persistent data), the PalmOS system call checks the address, directs the external chip not to intercept the next write operations if the address is correct (previously locked memory chunk), do the write then tells the chip to prevent further write operations in non-heap areas. They do not have true memory protection (which would be useless in their case), but they do offer a working alternative. That is why their devices almost never loose data, even when they run bogus applications (which can cause a data-safe device reset). Sam -- Samuel Tardieu -- http://www.rfc1149.net/sam -- sam@rfc1149.net