Category: Techie

We bought a new scanner today, an Epson Perfection 1660. We got it from PC World for £119, which is actually less than you would pay at most web shops. Not that I knew that before I went in to the shop. I went along to PC without having done my on-line reasearch to find out what the state of the scanner market is. A foolish move.

But on the other hand, I’m not a professional photographer or a graphic artist, so my needs are pretty basic. In the end, I chose the Epson for the following reasons:

• It has a USB2 interface, so it should be nicely fast. I don’t have USB2 on my PC yet (old-style USB only), but I will eventually.
• It has a built-in transparency adapter, so it can scan 35mm photo negatives and positives (slides). That’s cool. I didn’t know that this is now a common option on mid-priced scanners.
• It’s from a well-known brand. I think this is the fourth scanner we’ve had since 1995, and it’s the first one we’ve bought that wasn’t the cheapest unbranded thing we could find. Considering I’m not clued up about scanners in general, I figured that I couldn’t go too far wrong with an Epson.

As expected, the software that comes bundled with the scanner is rubbish, but that’s okay because all I need is the basic drivers. I’ll be using Paint Shop Pro 8 for everything else. (More about PSP 8 some other time. I’ve only started working with it, but already I can tell I’m going to love it. It’s slower than 7, and it’s a bit of a resource hog, but being able to write scripts for it makes up for a lot.)

A useful selection of Windows Registry tweaks at Registry Explorer.

Shortly after giving up on the SAProxy anti-spam tool the other week, I found an alternative tool that is doing the job very nicely: SpamBayes. It’s an add-in for MS Outlook that acts as a Bayesian filter for your email. (Big, big thanks to Anders Jacobsen for pointing it out.)

Whereas SpamAssassin (and hence SAProxy) uses a fixed set of rules to weed out spam, SpamBayes uses statistical methods to analyse your incoming mail. (See the article “A Plan For Spam” by Paul Graham for an explanation of the technique.) When you first set it up, you show it a bunch of mail that is good (“ham”) and a bunch of mail that is known to be bad (“spam”). It uses this to construct a profiling database. Each new piece of mail is checked against this database to figure out how likely it is to be spam. If it fits the profile, SpamBayes will automatically toss it into a “Spam” folder for you.

The neatest thing, though, is that the system is constantly adapting to new spam as it comes in. If a piece of email comes in that is spam, but doesn’t trigger the filter, then you click a button marked “Delete as Spam.” The offending message is added to the profiling database, so reducing the likelihood of similar junk mails getting through in future. Likewise, if an email is falsely tagged as spam, or as “possible spam” if the system is unsure, you click on the button marked “Recover from Spam.” This tells the profiling system that it made a mistake, and that it should adjust its probability weightings again. The system learns. SpamAssassin doesn’t, and so you have to keep updating it as time goes by, and as spammers learn to circumvent its fixed rules.

So far, it has been pretty good at catching incoming spam, but not quite as successful as SpamAssassin was. That’s probably because I didn’t have many examples of spam lying around in my mail to help it build up its initial profiling database. If you plan to use SpamBayes, I suggest you hang on to some of your recent spam so you can use it for teaching purposes.

An interesting side-effect of using a spam filter on my inbox is that I find incoming spam much more interesting now. Both SpamAssassin and SpamBayes allow you to see what it was that caused them to flag a particular piece of email as spam. SpamAssassin shows you what spam rules were triggered by a junk message, and SpamBayes shows you what words in the email contributed most to its overall Spam probability rating.

Ironically, this geeky fun factor means that I read (some of) my spam a lot more closely than I ever would have before. But in a forensic kind of way. Don’t be thinking that I actually spend time considering whether I really need some more Viagra this month. I keep careful track of my own supply, thanks.

Erm…

Related entries:

• SpamAssassin with SAProxy (3 May 2003)
• SAProxy update (4 May 2003)

Related Links

• SpamBayes home page

Our email is toast again. Interestingly, though, giant rodents are helping to fix it. From Telewest’s incident status page comes this news:

“The new hardware and the mailstores have now been installed and performance tuned. The new E420RS boxes have been introduced. The result is that we have processed half the queue overnight as we are delivering at an increased rat.”

What does the rat do with all the mail that’s being delivered at it, though? I hope it doesn’t nibble any bits off of all the backlogged email.

For a couple of years now we’ve had an external USB drive enclosure. We bought it originally for our CD-writer, so that we could easily move it between our PCs. Unfortunately, burning CDs proved to be totally unreliable through the USB connection. So we put a spare hard disk in it instead, and used it for backups, and for shuttling large files to and fro. (We have a wireless network here at home, but sometimes it’s useful to be able to move large quantities of data between home and work, and a USB hard drive is really useful for that.)

The downside of USB is that it’s really quite slow. It’s fine if all you’re doing moving is a couple of megabytes, but anything beyond that gets kinda painful. Which is probably why I haven’t been using it for backups quite as often as I ought to.

But over the weekend I bought a Firewire hard disk enclosure on Ebay. Firewire is some 40 times faster than USB, and boy does it show. The unit arrived this morning. I stripped the 80GB disk out of the old USB enclosure, strapped it into the (sleek, shiny) Firewire enclosure, turned it on, and there it was. Windows XP has all the necessary drivers built in, and the disk appeared instantly. To check that it was working, I copied a 100MB file over to it…in just a few seconds. Wow.

The new enclosure is also much quieter than the old one, because it doesn’t have a fan built in to it, so there’s no problem with leaving the drive switched on all, or most of the time. Now all I need to do is get some backups scripts going… (If anyone can recommend a good, simple backup utility for Windows, I’d be most grateful.)

Oh, and one other thing: don’t even think about going to PC World (or Dixons) to buy a Firewire cable. The cheapest ones they have will set you back £20. Twenty quid. Do a search for “firewire cable” on Ebay, and grab one for under a fiver.

SAProxy has successfully caught all fifteen pieces of spam that have arrived since I installed it on Friday, with no false positives. That’s good. What’s bad is that it has a habit of dying while I’m away from the computer.

My computer runs XP Pro unattached to a Windows domain, so that we can use the fast user-switching features. (Sometimes it’s faster for Abi to just log on to my computer and check her email rather than switching on her laptop.) What I’ve been finding is that when I come back to my session after being away for a couple of hours, whether another user session has taken place in that time or not, SAProxy will be gone, and I have to restart it.

I don’t know if it’s crashing or if it just figures that I don’t need it any more. It doesn’t leave behind any log files, nor does it write to the Windows Event log, so I just have no idea.

For the volume of spam I receive (low, by all accounts), I think it’s probably less annoying to just delete it when it arrives rather than to restart SAProxy whenever I resume a session. It should be running as a service rather than as a user program anyway. I reckon I’ll give it another chance when the product has matured a bit.

Related entries:

• SpamAssassin with SAProxy (3 May 2003)
• SpamBayes (17 May 2003)

Related Links

• SAProxy Home Page