Technology

Dear Valued Customer

I have been a very loyal customer of DynDns for quite sometime now, but a few days ago the following email dropped into my mailbox:

Dear Valued Customer:
The hostname, slug.xxx.co.uk, in account ABCDEF, has
been blocked for abuse. This action has been taken due to the
receipt of multiple updates originating from the same IP
address.
...

The message was from DynDns and was sent in response to the actions of my incorrectly configured DNS update client. What surprised me was just how taken aback I was at the use of the term abuse. As someone who has been using the Internet since some time before the introduction of the web browser I was shocked that I could be accused of abuse. Surely there was some mistake. Nevertheless they were absolutely right.

According to dictionary.com:

a·buse
1. To use wrongly or improperly; misuse: abuse alcohol; abuse a privilege.
2. To hurt or injure by maltreatment; ill-use.
3. To force sexual activity on; rape or molest.
4. To assail with contemptuous, coarse, or insulting words; revile.
5. Obsolete. To deceive or trick.


And I was certainly using their service wrongly. The problem was in the way that I had configured my SLUG to update its own entry on DynDns so that I could always find it from work by its fully qualified domain name even if my non-fixed home IP address changed. My mistake was in not making its update rules quite strict enough. I was occasionally updating my DNS entry when it hadn't really changed and so I was violating the DnsDns Update Abuse Policy.

The best things may be abused.
  - The Penguin Dictionary of Proverbs.

I've fixed the problem now and hopefully I'm no longer an abuser but a valued customer once again.

Mounting the SLUG

Between the two of us, Fiona and I have a large collection of audio CDs, and an even larger stack of vinyl LPs which rarely see the light of day. I'd been planning for some time to find a mechanism that would make all of them more accessible. Over the Christmas period I purchased a Linksys NSLU2 (affectionately known as a SLUG) and a 250GB Buffalo DriveStation.

The DriveStation is an external USB hard drive and the SLUG is a device that makes up to 2 USB drives visible on a LAN. Assembly is simple: Connect the SLUG to a 10/100 LAN using a RJ-45 Ethernet connector and connect the DriveStation to one of the SLUG's two USB ports - it's as simple as that. Once both devices are powered up the SLUG can be configured and the DriveStation formatted through a web-browser interface and in less than 10 minutes from opening the boxes the system is ready to use.

In operation, the external drive looks exactly like a shared drive on a networked PC would look but with the SLUG playing the role of the PC. Neither device contains a cooling fan and so both are almost silent in operation. The SLUG is about 5 inches high, 4 inches deep and about an inch wide. The DriveStation is about 7 inches high, 6 inches deep and about 2 inches wide. Their small size allows them to be tucked away, out of sight, and in our case connected directly to a wireless router which means that the huge storage capacity is available from anywhere within the home over the wireless LAN.

So far so good, but the interesting stuff is yet to come. The SLUG is a Linux powered device around which a community of open source developers have built a modified firmware (Unslung) and operating system which can be really easily installed. The modifications retain all of the existing functionality of the Linksys default firmware but turn the device into an accessible Linux system too.

The SLUG makes its USB attached drives visible as Samba shares. Samba is the well established application that runs on Linux and UNIX systems that wish to allow portions of their file storage to be visible in a Microsoft Windows network. But by upgrading the SLUG to the Unslung firmware it is possible to install a host of other applications too.

One of the first changes I made was to install OpenSSH which allows me to securely connect to the device from another machine on a connected network and gain shell access to the SLUG. This made it easy to upgrade the system yet further.

Once we had ripped a significant number of our CDs to the device using Windows Media Player or iTunes I looked around at alternative ways of making the music available. Several mechanisms are possible:

1. Using a simple network share, and mapping it to a local drive, is sufficient for Windows Media Player to pick up the files and include them in its library. Similarly iTunes can be persuaded to work in the same way although you need to be careful to ensure that it doesn't attempt to make copies of the files on the PC from which it is running.
   
2. The free package mt-daapd is a great way to make audio on the SLUG accessible from systems running iTunes on the local LAN.
   
3. The very reasonably priced TwonkyVision package is a UPnP server that can deliver both audio and video from the SLUG to other network connected devices. The number of appliances capable of working with TwonkyVision is growing rapidly.
   

I tend to use Windows Media Player from my laptop and so the simple network share solution works for me.

The OpenVPN package for the SLUG enables you to take things a stage further. Installing OpenVPN allows a secure network connection to be made between two machines or two networks over the Internet. For me, this enables me to call up music stored on the SLUG at home from my work environment and play it through Windows Media Player as if it was stored locally.

I'm currently looking at hardware developments, such as the Noxon-2 or the Zensonic Z500, with a view to purchasing a UPnP capable device that will allow me to stream video direct to the lounge or music direct to any room in the house. Why get up to change a CD every half hour when you can compile a complete playlist of music in advance and forget about it!

Oh and, what to do with the hundreds of gigabytes of remaining storage? Well, it's nice to know that somewhere, tucked away in the house, is a quiet and insignificant looking unit that contains a complete backup copy of all those files and photos that you think you have on DVD.

A COMDEX Footnote

Tidying out some papers this weekend I came across a copy of an editorial from BYTE magazine for February 1982 covering the November 1981 COMDEX exhibition in Las Vegas. Right at the foot of the article, in a section headed "Other Software Developments", the editor notes:

Intel has signed agreements with both Microsoft and Digital Research to distribute both companies' operating systems for a wide variety of Intel microcomputer systems and boards. This is a continuation of an interesting phenomenon that began when IBM announced it was going to make available both Microsoft's DOS operating system and CP/M-86 for the IBM Personal Computer. With corporate giants like Intel giving Microsoft and Digital Research a boost, it appears that both families of operating systems will coexist for quite some time.

Within three years the game was pretty much up for Digital Research's CP/M with Microsoft's MS-DOS gaining popularity. Digital Research almost came back again with DR-DOS but by then the goal posts had moved towards the GUI arena.

Thirty Years of Sharing

The January 2006 edition of Dr Dobbs journal runs an article entitled Dr Dobb's Journal @ 30 in which Michael Swaine tells the history of the development of the magazine from its birth in early 1976 as Dr. Dobb's Journal of Computer Calisthenics & Orthodontia to its current form. The magazine was conceived at the point in time where the prospect of building or owning a personal computer became a financial reality for many hobbyists and the excitement that accompanied it was easy to sample.

A number of hardware vendors began turning out microcomputer kits which consisted of:

• A simple CPU, such as Intel's new microprocessor chip developed for the calculator market.
• A storage device which might be a fixed or floppy disk, a magnetic or paper tape or more commonly a cassette recorder.
• Some form of I/O device which, given a suitable interface, might be a teletype or even a keyboard and display but other times was little more than a set of dip switches and lights.

The concern among the hardware vendors was that people would not find an application for the hardware and so the marketers of the time declared that their use was "limited only by your imagination".

In common with other electronic and computing magazines of the late 1970s and early 1980s, the journal retained a hands-on hobbyist feel even as more and more business application began to fill the non-editorial and classified pages. The emphasis was on sharing information to further extend the boundaries of what could be achieved on a limited budget - the journal even published a 4K BASIC language implementation in hex to key into the Altair.

In the 1980s, magazines commonly published listings as part of an article or in an appendix. When the computer games craze began, it was common to return from the newsagent with a fresh copy of a favourite computing magazine and begin the process of keying in pages of BASIC listing in the hope of playing what most modern teenagers today wouldn't recognise as a game. Often the listing would contain a printing error and the following edition of the magazine would print the corrections required to make the game run.

Over the decades the journal published volumes of source code, ranging from byte-saving coding tricks for the 8080, Steve Wozniak's floating-point routines for the 6502, Lawrence Livermore Labs BASIC, John Starkweather's PILOT, implementations of PASCAL and FORTH, the full source code for an 8080 kernel, a portable screen-oriented editor and, very importantly, two C compilers and the beginnings of a toolset in C. All of these tools were freely available for the use of its readers.

Almost thirty years ago Jim Warren, the incumbent editor, wrote:

It is this open sharing that particularly delights me...We must all do what we can to encourage it. The sharing of ideas...allows us to stand on one another's shoulders, instead of standing on one another's feet...So continue to share your ideas, and continue to share your excitement.

Malware Recovery

How does the ordinary non-technical PC user survive an attack by spyware or a virus? Do they just ignore the problem? And if so, how many people in the world are currently using PCs that are in some way infected? Do they take the PC to their local PC shop, do they figure out how to fix the problem or do they just live with it?

In the last two weeks I've seen two PCs become so infected by a virus that the simplest remedy has been to re-install Windows XP and, of course, that's only the start of the problem. The operating system is often the easiest part of a PC to restore. The applications are frequently more troublesome.