From owner-freebsd-questions Sun Jan 21 21:57:29 2001 Delivered-To: freebsd-questions@freebsd.org Received: from www.evil.2y.net (ip-216-23-53-20.adsl.one.net [216.23.53.20]) by hub.freebsd.org (Postfix) with ESMTP id 5E24A37B69B; Sun, 21 Jan 2001 21:57:02 -0800 (PST) Received: (from cokane@localhost) by www.evil.2y.net (8.11.1/8.11.1) id f0M69Cm02307; Mon, 22 Jan 2001 01:09:12 -0500 (EST) (envelope-from cokane) Date: Mon, 22 Jan 2001 01:09:11 -0500 From: Coleman Kane To: Luigi Rizzo Cc: Josef Karthauser , freebsd-hackers@FreeBSD.ORG, freebsd-questions@FreeBSD.ORG Subject: Re: Does anyone know how to let fd0.1720 be bootable? Message-ID: <20010122010910.A2151@cokane.yi.org> References: <20010121195839.C6250@tao.org.uk> <200101212312.f0LNC9u28668@iguana.aciri.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-md5; protocol="application/pgp-signature"; boundary="vkogqOf2sHV7VnPd" X-Mailer: Mutt 1.0.1i In-Reply-To: <200101212312.f0LNC9u28668@iguana.aciri.org>; from rizzo@aciri.org on Sun, Jan 21, 2001 at 06:13:14PM -0500 X-Vim: vim:tw=70:ts=4:sw=4 Sender: owner-freebsd-questions@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG --vkogqOf2sHV7VnPd Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable I had issues with this when I was doing some bootsector ASM coding. Basical= ly, you have to set up the disk header (first 32 bytes of sector 1?) to tell the bios how many sectors your disk has. Many BIOSes will still only do 18 sect= ors anyway, though. I can't remember the exact layout of the disk header, but i= t is usually started with a JMP NEAR instruction past the info header (3 bytes), followed by a short OS signature (8 bytes?) and then the disk info that is typically passed in INT 13 calls. Luigi Rizzo had the audacity to say: >=20 > > On Sat, Jan 20, 2001 at 01:19:17PM -0800, Luigi Rizzo wrote: > > > > I think this is a BIOS issue. I don't think any BIOS will let you > > > > boot from arbitrarily-formatted floppies :) > > >=20 > > > the 1480 format works. > >=20 > > Have you got this working now - or was it the larger size that didn't > > work? >=20 > 1480 always worked for me on the system i tried -- except on vmware. > i it was the 1720k format where i had problems which i could not > solve despite a number of different attempts at telling the > bios that i was using 21 sectors/track. >=20 > cheers > luigi > ----------------------------------+--------------------------------------= --- > Luigi RIZZO, luigi@iet.unipi.it . ACIRI/ICSI (on leave from Univ. di Pi= sa) > http://www.iet.unipi.it/~luigi/ . 1947 Center St, Berkeley CA 94704 > Phone: (510) 666 2927 > ----------------------------------+--------------------------------------= --- >=20 >=20 > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-hackers" in the body of the message >=20 --vkogqOf2sHV7VnPd Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.4 (FreeBSD) Comment: For info see http://www.gnupg.org iD8DBQE6a86DERViMObJ880RAeJhAJ0XLozCA6C7Sh6okuSP/AAzqZWyBwCfZ7Yx U7kPhHnlYCL+2gzCCEBE9cs= =/fTz -----END PGP SIGNATURE----- --vkogqOf2sHV7VnPd-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message