From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263624AbTDYSUa (ORCPT ); Fri, 25 Apr 2003 14:20:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263635AbTDYSUa (ORCPT ); Fri, 25 Apr 2003 14:20:30 -0400 Received: from chaos.analogic.com ([204.178.40.224]:10123 "EHLO chaos.analogic.com") by vger.kernel.org with ESMTP id S263624AbTDYST2 (ORCPT ); Fri, 25 Apr 2003 14:19:28 -0400 Date: Fri, 25 Apr 2003 14:34:04 -0400 (EDT) From: "Richard B. Johnson" X-X-Sender: root@chaos Reply-To: root@chaos.analogic.com To: John Bradford cc: Matthew Sell , Stewart Smith , Linux Kernel Mailing List Subject: Re: versioned filesystems in linux (was Re: kernel support for In-Reply-To: <200304251813.h3PIDSug001857@81-2-122-30.bradfords.org.uk> Message-ID: References: <200304251813.h3PIDSug001857@81-2-122-30.bradfords.org.uk> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 25 Apr 2003, John Bradford wrote: > > > Just wondering how difficult it would be to make a 9-track tape drive > > > from scratch, and connect it up to the parallel port... Do you think > > > that old hard disk motors, from 5.25" MFM disks be powerful enough for > > > the 120IPS tape transport? > > > > The disk-drive motors, even for the 5.25 floppies were pancake motors > > designed to directly turn the floppy, or run a belt with a small > > ratio. You need a motor that runs at relatively high speed to turn the > > capstan. If the capstan was 1 inch in circumference (about 0.2'' in > > diameter), you need 120 revs/sec = 7200 r.p.m. You won't do this with > > a floppy motor. > > I was thinking of hard disk motors... Actually, some of those would > be 3600 r.p.m., so if we used a large capstan, we might be in with a > chance :-). (You'd really need to drive the actual reels as well, > though, I can't see us starting and stopping the whole thing very > quickly just using the capstan motor.) > > John. > Oh the hard-disk motor that drive the RA80 will rotate the building if it ever stalled. I understand that the mechanical designers for that make vacuum cleaners right out of college. Cheers, Dick Johnson Penguin : Linux version 2.4.20 on an i686 machine (797.90 BogoMips). Why is the government concerned about the lunatic fringe? Think about it.