From owner-freebsd-hackers Sat Nov 18 09:52:27 1995 Return-Path: owner-hackers Received: (from root@localhost) by freefall.freebsd.org (8.6.12/8.6.6) id JAA08571 for hackers-outgoing; Sat, 18 Nov 1995 09:52:27 -0800 Received: from irz301.inf.tu-dresden.de (irz301.inf.tu-dresden.de [141.76.1.11]) by freefall.freebsd.org (8.6.12/8.6.6) with ESMTP id JAA08564 for ; Sat, 18 Nov 1995 09:52:12 -0800 Received: from sax.sax.de by irz301.inf.tu-dresden.de (8.6.12/8.6.12-s1) with ESMTP id SAA09218; Sat, 18 Nov 1995 18:51:03 +0100 Received: by sax.sax.de (8.6.11/8.6.12-s1) with UUCP id SAA16983; Sat, 18 Nov 1995 18:51:00 +0100 Received: (from j@localhost) by uriah.heep.sax.de (8.6.12/8.6.9) id SAA23460; Sat, 18 Nov 1995 18:14:26 +0100 From: J Wunsch Message-Id: <199511181714.SAA23460@uriah.heep.sax.de> Subject: Re: DELAY's in syscons To: hm@altona.hamburg.com Date: Sat, 18 Nov 1995 18:14:25 +0100 (MET) Cc: bde@zeta.org.au, freebsd-hackers@FreeBSD.ORG, hosokawa@mt.cs.keio.ac.jp Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) In-Reply-To: from "Hellmuth Michaelis" at Nov 18, 95 01:38:27 pm 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: 736 Sender: owner-hackers@FreeBSD.ORG Precedence: bulk As Hellmuth Michaelis wrote: > > >From the keyboard of Bruce Evans: > > > DELAY(n) only delays n-20 usec on an infinitely fast machine so it > > shouldn't be called with n <= 20 unless the precise delay doesn't matter. > > Syscons and pcvt call it with delays <= 10 usec when the precise delay > > does matter. > > If not told otherwise, pcvt does NOT use DELAY() for exactly the reason > you just describe. DELAY() is supposed to be safer than the inb(0x84) hack. It uses the clock. (No, this is no longer the crude DELAY() macro 386BSD 0.1 has been so proud of. :-) -- cheers, J"org joerg_wunsch@uriah.heep.sax.de -- http://www.sax.de/~joerg/ -- NIC: JW11-RIPE Never trust an operating system you don't have sources for. ;-)