From owner-freebsd-hackers Mon Jun 12 16:05:17 1995 Return-Path: hackers-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id QAA07113 for hackers-outgoing; Mon, 12 Jun 1995 16:05:17 -0700 Received: from disperse.demon.co.uk (disperse.demon.co.uk [158.152.1.77]) by freefall.cdrom.com (8.6.10/8.6.6) with SMTP id QAA07087 for ; Mon, 12 Jun 1995 16:05:11 -0700 Received: from post.demon.co.uk by disperse.demon.co.uk id aa03113; 13 Jun 95 0:03 +0100 Received: from bagpuss.demon.co.uk by post.demon.co.uk id aa18451; 13 Jun 95 0:03 +0100 Received: (karl@localhost) by bagpuss.demon.co.uk (3.1/3.1) id OAA00725; Mon, 12 Jun 1995 14:48:46 +0100 From: Karl Strickland Message-Id: <199506121348.OAA00725@bagpuss.demon.co.uk> Subject: Re: DAT drive advice needed To: Torbjorn Granlund Date: Mon, 12 Jun 1995 14:48:45 +0100 (BST) Cc: hackers@freebsd.org, sef@cygnus.com In-Reply-To: <199506112111.VAA15317@insanus.matematik.su.se> from "Torbjorn Granlund" at Jun 11, 95 11:11:08 pm X-Mailer: ELM [version 2.4 PL23] Content-Type: text Content-Length: 2239 Sender: hackers-owner@freebsd.org Precedence: bulk > > Well, I bought a complete system where almost every component had some > problem, and I had to return both the SCSI controller and the Graphics card > to get properly working ones. After all that headache, the system now works > great. The combination Pentium90/Triton/QuantumGPS/FreeBSD 2.0.5- actually > makes the fastest system I have ever used! > > It is time to get a DAT drive, and I'd like to avoid to get another lemon. > > I'd like to get a high-quaility DAT drive, and I need to send tapes to > people and recieve tapes from people. The HP drives vary in capacity a lot, > but the prices are within a few hundred dollars. So, from that perspective, > I'd get the 16 Gb drive, for just $1000 at NCA. > > But will FreeBSD and the drive be able to write tapes that most older DAT > drives will be able to read? If not, what drives will allow me to ship > tapes to others? > > Torbjorn > Im not an expert on this, but heres what I remember from when I was looking into this 12 months or so ago. There are 2 DAT encoding formats - DDS1 (or just DDS) and DDS2. I believe DDS2 drives can also read/write DDS1. The reasons why the drives vary in capacity are: 1. A drive is capable of DDS2, which can store more per inch of tape than DDS1. 2. Different length tapes are used. With DDS1 recording, 60m typically gets you 1.3Gb, 90m gets you 2.0Gb. I believe DDS2 will let you roughly double that. There are also 120m tapes for use in DDS2 drives which you need for 16Gb. 3. Compression - on drives that have it, it can be turned on & off via both hardware and software. In short I believe any top of the range DAT can read any tapes, and write any tapes. If you want your tapes to be readable by the largest number of people, you should use the lowest common denominator, which is probably DDS1 encoding, no compression, 60m tapes. This is from memory, if its wrong, Im sure someone will correct it :) -- ------------------------------------------+----------------------------------- Mailed using ELM on FreeBSD | Karl Strickland PGP 2.3a Public Key Available. | Internet: karl@bagpuss.demon.co.uk |