Date: Fri, 25 Aug 1995 08:09:45 +0200 (MET DST) From: J Wunsch <j@uriah.heep.sax.de> To: freebsd-hackers@freebsd.org (FreeBSD hackers) Subject: Re: ISDN Anyone? Message-ID: <199508250609.IAA01137@uriah.heep.sax.de> In-Reply-To: <199508250344.NAA29018@godzilla.zeta.org.au> from "Bruce Evans" at Aug 25, 95 01:44:15 pm
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As Bruce Evans wrote: > > ISA parallel ports have significantly higher overheads that 16450s. They > generate an interrupt per byte for output and an interrupt per nybble for > input. They take about twice as many i/o's per byte for output and even > more for input. The are only "fast" compared with serial ports because > serial ports run at a fixed, relatively low, speed. You can also say it in other words: they are not allowed to burn all CPU cycles (provided you don't have a 368/16 only). :-) -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ Never trust an operating system you don't have sources for. ;-)
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