From owner-freebsd-hackers Thu Aug 24 23:27:12 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.FreeBSD.org (8.6.11/8.6.6) id XAA28068 for hackers-outgoing; Thu, 24 Aug 1995 23:27:12 -0700 Received: from irz301.inf.tu-dresden.de (irz301.inf.tu-dresden.de [141.76.1.11]) by freefall.FreeBSD.org (8.6.11/8.6.6) with SMTP id XAA28041 for ; Thu, 24 Aug 1995 23:27:07 -0700 Received: from sax.sax.de by irz301.inf.tu-dresden.de with SMTP (5.67b+/DEC-Ultrix/4.3) id AA17853; Fri, 25 Aug 1995 08:27:02 +0200 Received: by sax.sax.de (8.6.11/8.6.12-s1) with UUCP id IAA13545 for freebsd-hackers@freebsd.org; Fri, 25 Aug 1995 08:27:01 +0200 Received: (from j@localhost) by uriah.heep.sax.de (8.6.11/8.6.9) id IAA01137 for freebsd-hackers@freebsd.org; Fri, 25 Aug 1995 08:09:45 +0200 From: J Wunsch Message-Id: <199508250609.IAA01137@uriah.heep.sax.de> Subject: Re: ISDN Anyone? To: freebsd-hackers@freebsd.org (FreeBSD hackers) Date: Fri, 25 Aug 1995 08:09:45 +0200 (MET DST) Reply-To: freebsd-hackers@freebsd.org (FreeBSD hackers) In-Reply-To: <199508250344.NAA29018@godzilla.zeta.org.au> from "Bruce Evans" at Aug 25, 95 01:44:15 pm Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) X-Phone: +49-351-2012 669 X-Mailer: ELM [version 2.4 PL23] Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit Content-Length: 651 Sender: hackers-owner@freebsd.org Precedence: bulk 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. ;-)