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Backer For Linux

The Backer for Linux project:  a project to develop a Linux device driver for Danmere's Backer video tape backup devices.

Last update:  2003/05/07

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What is a Backer?

A company in England named Danmere Technologies Ltd. (now 4TV Ltd.) used to sell a line of devices that allow you to save data on regular video tape.  They called them Backers and they came in three flavours:  an external version that plugs into an ECP parallel port and two internal versions that sit in ISA bus slots.  If you remember the days of using audio cassettes to store programs and data then the operation of a Backer device should be familiar to you.

Unfortunately, Danmere would neither provide Linux drivers for their products nor were they willing to release programming information to developers who were willing to do so for them.  The last e-mails I sent to them on the subject were ignored.  Finally, as of the fall of 2002, their web site has disappeared.  Oh well...

It turns out the Backer hardware is extremely simple and contains virtually no data processing intelligence whatsoever.  It plays the role of a modem, blindly modulating a byte stream into and demodulating it out of a video signal.  External software is required to perform all data framing, error correction, etc..  The advantage of this design is that it reduces the cost of the hardware and permits a great deal of flexibility in matching the tape format to the video equipment in use.

What is this software?

The software discussed on this page is a Linux device driver for Backers that allows you to use them as though they were standard magnetic tape devices.  With this driver, you can perform backups of your system using, for example, GNU tar or the archive software of your choice.

You can download the latest stable and unstable versions of the driver from here.

The driver version numbering works as follows.  The version major number (the number to the left of the decimal place) indicates the native tape format.  This number is increased when the driver's tape format changes in a way that makes it incompatible with previous versions.  The minor number (the number to the right of the decimal place) indicates the release number.  Minor numbers less than 100 are stable releases and will all use the same, well tested, tape format.  Minor numbers greater than or equal to 100 are unstable, developmental, releases leading up to the next major release.  Developmental releases might not be well tested and might not use the same format from release to release.

Capabilities (stable 3.x drivers)

System Requirements

These are the system requirements that I am aware of.  Most of them are not fundamental and could be relaxed if people with the appropriate systems could help test and debug the code.

Related Links

Support Information

My name is Kipp Cannon and I can be contact by e-mail at SourceForge:  kcannon at


This document uses the new binary units recommended by the International Electrotechnical Commision.  So 1 MB is 106 bytes while 1 MiB is 220 bytes;  1 GB is 109 bytes while 1 GiB is 230 bytes; etc..


This project has been conducted entirely without the support, participation or even interest of Danmere, Ltd. (now 4-TV).  Please consider the following: