From owner-freebsd-hackers Thu Oct 28 13:20:48 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from sax.sax.de (sax.sax.de [193.175.26.33]) by hub.freebsd.org (Postfix) with ESMTP id 16F7014C08 for ; Thu, 28 Oct 1999 13:20:34 -0700 (PDT) (envelope-from j@uriah.heep.sax.de) Received: (from uucp@localhost) by sax.sax.de (8.8.8/8.8.8) with UUCP id WAA17466 for freebsd-hackers@freebsd.org; Thu, 28 Oct 1999 22:20:30 +0200 (CEST) (envelope-from j@uriah.heep.sax.de) Received: (from j@localhost) by uriah.heep.sax.de (8.9.3/8.9.1) id WAA01569; Thu, 28 Oct 1999 22:06:10 +0200 (MET DST) (envelope-from j) Date: Thu, 28 Oct 1999 22:06:10 +0200 (MET DST) Message-Id: <199910282006.WAA01569@uriah.heep.sax.de> Mime-Version: 1.0 X-Newsreader: knews 0.9.8 Reply-To: joerg_wunsch@uriah.heep.sax.de (Joerg Wunsch) Organization: Private BSD site, Dresden X-Phone: +49-351-2012 669 X-PGP-Fingerprint: DC 47 E6 E4 FF A6 E9 8F 93 21 E0 7D F9 12 D6 4E References: <199909292346.BAA03499@dorifer.heim3.tu-clausthal.de> From: j@uriah.heep.sax.de (J Wunsch) Subject: Re: 2.88Mb floppies X-Original-Newsgroups: local.freebsd.hackers To: freebsd-hackers@freebsd.org Content-Type: text/plain; charset=us-ascii Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Oliver Fromme wrote: > I once programmed low-level FDC stuff under DOS, so I'm a bit I under CP/M, that's why i wrote the floppy formatter for 386BSD. ;-) > familiar with this... The difference between 1.44 and 2.88 Mb > floppies is that the latter use 36 sectors per track and twice > the data rate (1 MBit/s). So the entry should look like this: Alas, there's way more of differences than this when it comes to 2.88 MB. The higher data rate makes it now painfully obvious that the entire timing is misdesigned in the driver, or actually rather that the entire FDC design is crippled. :) Seeks will no longer work reliably on a number of drives then (if you double the FDC clock rate once again) since the stepper gets overclocked. Also, there's something called `perpendicular mode' (which i never fully groked what it's really for) you need to enable for 2.88 MB. -- 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. ;-) To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message