From owner-freebsd-hackers Sun May 4 12:14:43 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.5/8.8.5) id MAA11371 for hackers-outgoing; Sun, 4 May 1997 12:14:43 -0700 (PDT) Received: from phaeton.artisoft.com (phaeton.Artisoft.COM [198.17.250.50]) by hub.freebsd.org (8.8.5/8.8.5) with SMTP id MAA11366 for ; Sun, 4 May 1997 12:14:40 -0700 (PDT) Received: (from terry@localhost) by phaeton.artisoft.com (8.6.11/8.6.9) id MAA14427; Sun, 4 May 1997 12:11:56 -0700 From: Terry Lambert Message-Id: <199705041911.MAA14427@phaeton.artisoft.com> Subject: Re: DXF?? format disk To: dec@phoenix.its.rpi.edu (David E. Cross) Date: Sun, 4 May 1997 12:11:56 -0700 (MST) Cc: terry@lambert.org, joerg_wunsch@uriah.heep.sax.de, hackers@FreeBSD.ORG In-Reply-To: from "David E. Cross" at May 4, 97 02:50:40 pm X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-hackers@FreeBSD.ORG X-Loop: FreeBSD.org Precedence: bulk > I just checked... it is almost exactly 2MB (it is 1.95MB, with DOS > overhead, so probably 2MB exact, raw format) > > It would be convienient for me for moving data on floppies. Most of the > images I work on are about 1.5-1.9M, convieniently large enough to not fit > on a single disk. This would be too large a number for use of the "additional tracks" technique; as far as I know, the stepper motor can only go maybe 3-4 more tracks before go hit the mechanical stop, and that's still "iffy" on most older hardware. If they have this density, then they are playing with the encoding and sync marks. It is likely that this is "read-only" for most PC hardware, since it would rely on reduced write head width to get the magnetic domains small enough that they would still be discretely discernable on read. As far as I know, this technique was only used as copy protection on some games, and for OS/2 distribution by IBM. Are you sure these are MS manufactured disks you are talking about? If so, I'd be interested in knowing the MS product they are for. In any case, it's unlikely that you could write these. Have you considered buying a 2.88M floppy drive instead? (NB: you still would not be able to write these disks on a 2.88 drive.. the 2.88 drive operates by doubling th track density, so while the write head is thinner, it's thinner width, not length). Alternately, could you use some good data compression to reduce the image size? Attack the problem from the other direction? Regards, Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers.