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 X-Google-Thread: 103376,dd6489250ee6bc95 X-Google-Attributes: gid103376,public Path: g2news1.google.com!news1.google.com!news.glorb.com!news-stoc.telia.net!217.209.241.210.MISMATCH!news-stod.telia.net!telia.net!masternews.telia.net.!newsc.telia.net.POSTED!not-for-mail From: =?ISO-8859-1?Q?Bj=F6rn_Persson?= User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4.1) Gecko/20031114 X-Accept-Language: sv, sv-se, sv-fi, en-gb, en-us, en MIME-Version: 1.0 Newsgroups: comp.lang.ada Subject: Re: Poor tasking performance References: In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Message-ID: Date: Sun, 20 Jun 2004 09:18:35 GMT NNTP-Posting-Host: 217.209.116.179 X-Complaints-To: abuse@telia.com X-Trace: newsc.telia.net 1087723115 217.209.116.179 (Sun, 20 Jun 2004 11:18:35 CEST) NNTP-Posting-Date: Sun, 20 Jun 2004 11:18:35 CEST Organization: Telia Internet Xref: g2news1.google.com comp.lang.ada:1712 Date: 2004-06-20T09:18:35+00:00 List-Id: Robert I. Eachus wrote: > And finally we are back to polling for some devices because the overhea= d=20 > is lower than using interrupts... I can imagine that, but I doubt the keyboard is one of those devices. > For keyboard input most systems, most of the time, use a protocol where= =20 > _some_ keys cause interrupts, and others just place the data in a=20 > buffer. When the carriage return or whatever occurs, the entire buffer= =20 > is read. When I press a key, in most cases either a character shows up on the=20 screen or some action is triggered. I suppose modifier keys (Shift,=20 Ctrl, ...) and "dead" accents could be buffered. Right now I can only=20 come up with one case when letters don't have to be read immediately:=20 when the user is typing a password and characters are neither echoed nor = indicated with asterisks. --=20 Bj=F6rn Persson jor ers @sv ge. b n_p son eri nu