From owner-freebsd-hackers Sat Feb 24 04:39:26 1996 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.7.3/8.7.3) id EAA25615 for hackers-outgoing; Sat, 24 Feb 1996 04:39:26 -0800 (PST) Received: from genesis.atrad.adelaide.edu.au (genesis.atrad.adelaide.edu.au [129.127.96.120]) by freefall.freebsd.org (8.7.3/8.7.3) with ESMTP id EAA25594 for ; Sat, 24 Feb 1996 04:39:16 -0800 (PST) Received: from msmith@localhost by genesis.atrad.adelaide.edu.au (8.6.12/8.6.9) id XAA26973; Sat, 24 Feb 1996 23:08:03 +1030 From: Michael Smith Message-Id: <199602241238.XAA26973@genesis.atrad.adelaide.edu.au> Subject: Re: 230.400 bps on serial port To: bde@zeta.org.au (Bruce Evans) Date: Sat, 24 Feb 1996 23:08:02 +1030 (CST) Cc: msmith@atrad.adelaide.edu.au, petzi@zit.th-darmstadt.de, hackers@FreeBSD.org In-Reply-To: <199602241015.VAA30131@godzilla.zeta.org.au> from "Bruce Evans" at Feb 24, 96 09:15:33 pm MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@FreeBSD.org Precedence: bulk Bruce Evans stands accused of saying: > All wrong. > > - 230400 bps full speed bidirectional generates at most 23040 / 16 + > 23040 / 14 = 3085 interrupts/second. bps/Bps. Argh 8( I plead sheer stupidity, with lack of breakfast as a mitigating circumstance 8( > - IDE disks have no effect on serial communications under FreeBSD. > (Bus-hogging DMA controllers may have an adverse affect if they steal > too many cycles.) Hmm, that means splbio() is lower than spltty(), correct? That's a genuine misunderstanding on my part. (Assumption that PIO to/from disk would occur at splbio, also wrong?) > Bruce I should go back to bed. 8( -- ]] Mike Smith, Software Engineer msmith@atrad.adelaide.edu.au [[ ]] Genesis Software genesis@atrad.adelaide.edu.au [[ ]] High-speed data acquisition and (GSM mobile) 0411-222-496 [[ ]] realtime instrument control (ph/fax) +61-8-267-3039 [[ ]] Collector of old Unix hardware. "Where are your PEZ?" The Tick [[