From owner-freebsd-hardware Fri Mar 27 18:30:18 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id SAA14101 for freebsd-hardware-outgoing; Fri, 27 Mar 1998 18:30:18 -0800 (PST) (envelope-from owner-freebsd-hardware@FreeBSD.ORG) Received: from godzilla.zeta.org.au (godzilla.zeta.org.au [203.2.228.19]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id SAA14090 for ; Fri, 27 Mar 1998 18:30:12 -0800 (PST) (envelope-from bde@godzilla.zeta.org.au) Received: (from bde@localhost) by godzilla.zeta.org.au (8.8.7/8.8.7) id NAA13946; Sat, 28 Mar 1998 13:25:33 +1100 Date: Sat, 28 Mar 1998 13:25:33 +1100 From: Bruce Evans Message-Id: <199803280225.NAA13946@godzilla.zeta.org.au> To: bob@wbs.net, jkh@time.cdrom.com Subject: Re: 12.0 GB Quantum Bigfoot TX IDE seen as 8.4 GB Cc: freebsd-hardware@FreeBSD.ORG Sender: owner-freebsd-hardware@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org >With LBA off, BIOS defaults to CHS, and as previously mentioned shows 23361 >cyl/16 hd/63 sec on the BIOS display (still 12 GIG), but feeBSD seems to >max out at 16383 cyl/16 hd/63 sec (still adds up to 8.4 GIG)... FreeBSD always uses CHS with whatever limits the drive reports (max 65535 cyl/16 hd/255 sec) (128G). Drives don't report more than 63 sectors due to BIOS braindamage. Apparently some drives don't report more than 16383 cylinders. I don't know of any BIOS bugs for >= 16384 cylinders. CHS BIOSes break at only 1024 cylinders. FreeBSD used to have a sign extension bug for >= 32768 cylinders. >Interestingly, I found this item (from Aug 96) that suggests there may be >an 8 GIG limit... > > "With BIOS LBA, the hard disk size limitation is virtually removed (well, > pushed up to 8 Gigabytes anyway). If you have an LBA BIOS, you can put > FreeBSD or any OS anywhere you want and not hit the 1024 cylinder limit." A BIOS limit. FreeBSD doesn't use the BIOS except for booting, but may be affected by drives dumbing down things so that BIOSes sort of work. Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message