Date: Thu, 28 Oct 1999 22:06:10 +0200 (MET DST) From: j@uriah.heep.sax.de (J Wunsch) To: freebsd-hackers@freebsd.org Subject: Re: 2.88Mb floppies Message-ID: <199910282006.WAA01569@uriah.heep.sax.de> References: <199909292346.BAA03499@dorifer.heim3.tu-clausthal.de>
next in thread | previous in thread | raw e-mail | index | archive | help
Oliver Fromme <olli@dorifer.heim3.tu-clausthal.de> 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
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199910282006.WAA01569>