From owner-freebsd-small Thu Dec 7 14: 5:34 2000 From owner-freebsd-small@FreeBSD.ORG Thu Dec 7 14:05:32 2000 Return-Path: Delivered-To: freebsd-small@freebsd.org Received: from gta.com (mailgate.gta.com [199.120.225.4]) by hub.freebsd.org (Postfix) with ESMTP id 6DE2537B400 for ; Thu, 7 Dec 2000 14:05:31 -0800 (PST) Received: from gta.com (GTA internal mail system) by gta.com id RAA39082; Thu, 7 Dec 2000 17:03:36 -0500 (EST) Date: Thu, 7 Dec 2000 17:03:36 -0500 (EST) Message-Id: <200012072203.RAA39082@gta.com> From: Larry Baird To: small@freebsd.org Cc: Luigi Rizzo Subject: Re: non-standard floppy formats ? In-Reply-To: <200012070036.eB70a2X00376@iguana.aciri.org> User-Agent: tin/1.4.2-20000205 ("Possession") (UNIX) (FreeBSD/3.5-STABLE (i386)) Sender: owner-freebsd-small@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG In article <200012070036.eB70a2X00376@iguana.aciri.org> you wrote: > Hi, > i was trying to make picobsd work with non-standard floppy > formats (1722k specifically), but i am having a hard time. > Basically, the boot2 code says "Not ufs", i think this is > because it tries to read from the disk using the BIOS > and the BIOS only knows about the 80 track/18 sector > format, and not the 82*21 format used for 1722k. Am i correct ? > This is really bad because in the additional 300K there would > be a lot of stuff one could squeeze in. I think the problem is in boot1.s of boot2. Look at the function read(). The first thing is does is do an int13 call to get the BIOS configuration of the floppy. The result that is causing you a problem is "cylinders per track" (returned in register cl). You could hardcode the code after the int13 to set register cl to your new floppy geometry. Larry -- ------------------------------------------------------------------------ Larry Baird | http://www.gnatbox.com Global Technology Associates, Inc. | Orlando, FL Email: lab@gta.com | TEL 407-380-0220, FAX 407-380-6080 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-small" in the body of the message