From owner-freebsd-stable Mon Nov 20 7:36: 0 2000 Delivered-To: freebsd-stable@freebsd.org Received: from siri.nordier.com (c2-dbn-84.dial-up.net [196.34.155.212]) by hub.freebsd.org (Postfix) with ESMTP id A87F537B479 for ; Mon, 20 Nov 2000 07:35:53 -0800 (PST) Received: (from rnordier@localhost) by siri.nordier.com (8.9.3/8.6.12) id RAA25621 for stable@FreeBSD.org; Mon, 20 Nov 2000 17:37:40 +0200 (SAST) From: Robert Nordier Message-Id: <200011201537.RAA25621@siri.nordier.com> Subject: Re: Dedicated disks (was: Dangerously Dedicated) To: stable@FreeBSD.org Date: Mon, 20 Nov 2000 17:37:39 +0200 (SAST) Reply-To: rnordier@FreeBSD.org In-Reply-To: <20001120192044.Q58333@echunga.lemis.com> from "Greg Lehey" at Nov 20, 2000 07:20:44 PM X-Mailer: ELM [version 2.5 PL3] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG Greg Lehey wrote: > > Why do you *insist* on calling it a "Microsoft partition table"?? > > Hmm. I was going to say "Because it was introduced with Microsoft > 2.0", but I'm no longer so sure. Reading the MS-DOS 2.11 source code, > it seems that they didn't have a partition table at the time. Of course they had a partition table at the time, and of course MS-DOS 2.11 used it: [io.sys] 1431 8d9fbe01 lea bx,[bx+0x1be] 1435 8b4740 mov ax,[bx+0x40] 1438 3d55aa cmp ax,0xaa55 143b 7539 jnz 0x1476 143d b90400 mov cx,0x4 1440 807f0401 cmp byte [bx+0x4],0x1 1444 7407 jz 0x144d 1446 83c310 add bx,byte +0x10 1449 e2f5 loop 0x1440 144b eb29 jmp short 0x1476 > Can anybody remember when it was introduced? In March 1983, with the release of PC-DOS 2.0. > Anyway, it's needed for "modern" Microsoft offerings, and not really > for much else. It's also not a UNIX partition table. Actually, the immediate reason for its introduction was in order to support dual-booting XENIX (Early SCO/Microsoft UNIX) on PCs. This is why the partition type numbering starts 1 DOS 2 XENIX 3 XENIX -- Robert Nordier rnordier@nordier.com rnordier@FreeBSD.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message