Booting Linux from a USB Stick using a Floppy

The trusty old Fujis that make up the bulk of the computers I deal with day-to-day tend to be pretty reliable, but I have noticed a few going down with (what I believe are) faulty disk drive controllers (to be fair, these machines are at least six years old). The system runs fine, all except seeing a hard drive.

I’d obviously heard of running a computer from a solid state disk of some sort, it’s not new. The Raspberry Pi runs off of an SD card and I’ve seen a few projects using Compact Flash. So rather than bin another machine, I thought I would experiment to see if I could get Linux to run from an old USB flash drive I have lying around (Windows was pushing it on size if nothing else).

At first I looked for a lightweight distro, something close enough to Windows in look that, should I put it in front of one of my users, it wouldn’t freak them out. Precise Puppy seemed to be the answer.

Once loaded it runs from RAM, which made it responsive, but the design was a bit hard on the eye and to save any changes permanently you had to remember to click a button to write to the USB stick, which was a slow and tedious process. It also seemed to asked me to confirm some settings every time it started, not great when a machine rebooted, I could already hear the support calls. The final straw was the difficulty in getting an RDP client working.

I went back to a distro I knew a bit better and which looked easier on the eye: Linux Mint.

Installing Linux

To be honest, once I’d decided on Mint, I didn’t do anything particularly special, just picked the USB drive as the installation drive after booting from a Live CD/DVD. It took a bit of time, but once it was installed it ran from there without needing to do anything else.

I decided on a 4GB drive as 2GB was a little tight should you want to install anything else (and Mint isn’t the slimmest by default, it isn’t designed to be).

You could also install it using something like UNetBootin I assume.

The only slight issue is on boot you get an error saying hd0 is out of space and you have to press a key to continue, whether it does or not has been a bit random, but a reboot usually sorts it out. Continue reading…

Second-Hand PCs Offer Great Savings

I’d normally buy computers brand new, but at work I’ve found a great source of cheap computers that do the job at knock-down prices: eBay. Businesses are always looking to save money, but most couldn’t cope without their computers. In our case they’re largely used as thin clients, along with running a web browser, perhaps an office suite and some have an email client. If you want to buy a new machine these days you’re looking at something with multi-gigahertz multi-core processors and truckloads of RAM that’ll set you back £250+. It’s overkill for what most people use their computers for.

I found a low-powered Atom processor more than up to the task for the majority of my use. Tablets and smartphones have much less processing power and significantly less RAM than a desktop, yet happily do everything from web surfing to games. Previously, I’ve asked whether Atom-powered computers were worth the money (and decided not). I can confirm that’s still the case because of what you can pick up second-hand.

My latest acquisitions on eBay were two Fujitsu-Siemens workstations with 2.4 GHz Pentium 4 processors and 1.5 GB of RAM. They came with copies of Windows XP Pro and are more than capable of doing what 99% of users need. Their specs weren’t cutting edge and these machines were about six years old. They’re not particularly power efficient, they had signs of wear and they use some non-standard parts, making replacing bits harder if they fail, but they only cost me £25 each (including delivery). That’s less than the cost of a Raspberry Pi!

Now, granted, that was just for a base unit (tower, whatever you call it), no keyboard, mouse or monitor. I could buy new ones of all of those for under £100, but I’m sure I could find them on eBay for much less (in fact I found whole systems — base unit, monitor, etc — for £99) and once you have them you don’t need them again, just upgrade your base unit as and when you need to.

If the specs on my machines don’t impress you, I found a dual-core 2.8 Ghz Pentium PC with 2 GB RAM and a 300 GB hard drive, with Windows 7 installed, for £100 (plus £10 postage). That’ll happily run Windows 8 and, if you’re capable of upgrading the RAM, will happily do almost any task you throw at it for years to come. Continue reading…

A Little Home Automation

I’ve mentioned elsewhere that I have a lamp timer and was finding it frustrating to have to manually change the on/off times throughout the year as the length of the day changes. One option I suggested using a computer to to give more flexibility and control.

Well I’ve been running with a setup that does use a computer for a few months now and it seems to be working well, so well that it’s controlling my Christmas lights too. In the end I didn’t wait for a Raspberry Pi (I already have a small Linux server that’s on 24/7, so just used that instead).

In my other article I posited using something like X10 to control it, but X10 plugs and controllers are fairly expensive. I had a set of three remote controlled plugs already and a bit of searching found that they could be controlled remotely. I got the set for free, but you can pick up similar ones in supermarkets and DIY places from as little as £5. Just be sure they adhere to one of the standards (such as Bye Bye Standby or Home Easy, which seem to be the most common in the UK). To send on and off signals I settled on a simple USB stick from a Swedish company to do just that.

The Transmitter

Telldus TellstickI opted for the Telldus TellStick, which isn’t cheap (though it’s the cheapest of their range), but it had good support on multiple platforms (including Linux) and saved me soldering or whatnot. It cost me £54.60 (inc VAT and postage) from Audon Electronics.

The unit is underwhelmingly small and looked a little disappointing when I opened the pack, but I plugged it in and followed the instructions to download and install the application and within minutes I was able to switch a socket on and off through the control centre software.

I was thinking of using the automation as an exercise to play about with Python, but I know PHP better and there seemed a fairly simple way to get that to work (plus I already had everything installed so could get a web front-end working no problem). Continue reading…

Computer Hardware Tool Kits

I doubt the rise in tablets, laptops and mini PCs will see the end of people building, repairing or modifying their computers, despite many being sealed, so a computer tool kit is invaluable. There are a number of kits available to buy and you only need a couple of tools to do 99% of the tasks you’ll ever attempt. You may even have many of the tools.

If you’re going to buy a specialist computer tool kit they range in size from a handful of tools to a whole briefcase and with prices to match. Having had to support computers both personally and professionally I thought I’d share what has actually been useful.

The Essentials

Part retriever/extractor

This is one of the most useful tools in my kit, especially when a screw gets away from you. Aside from being able to reach places my fat fingers can’t, it’s useful for putting screws back into locations deep in the case, generally you use this to get a turn or two so it’ll hold before you grab your screwdriver. It’ll also save you a lot scratches from the rough edges inside most cases.

Strong magnets generally aren’t recommended inside computer cases (or near electrical equipment in general), so the mechanical claw type is the best option.

Screwdrivers

For PCs it’s really down to a couple of Philips-type screwdrivers.  Sizes 1 and 2 should cover every application you’ll find on a PC as the case, motherboard, drives and expansion cards generally all use the same size screws across every different make and model.

I’d recommend fixed screwdrivers over the kind with removable bits (they’re usually  shorter and the bits can fall out). The removable bit types do allow you to pack a lot more types of screwdriver in a small space though (I do have one in one of my kits), but is this is your only screwdriver look for a set with an extension bar to help reach some of the screws hidden in the depths.

A couple of traditional fixed-head Philips screwdrivers and then one with interchangeable bits would probably be the ideal.

If you’re likely to be taking apart things like Apple computers, laptops, tablets or want to go hardcore on things like hard drives then some precision/jeweller’s screwdrivers and a kit including Torx bits will be necessary.

Don’t worry of they’re magnetised, the power in them won’t be enough to disturb the electronics. Continue reading…

Securely Wiping a Hard Disk

So you’ve bought a new computer and decided to be generous and donate your old one to a charity, or perhaps you’ve decided you need some more space and have upgraded your hard drive and are looking to sell the old one to recoup some cash.  You’ve remembered to format the drive, so you’re safe from someone reading your files, right?

Well, no.  You see, deleting files and formatting drives still leaves your files perfectly readable using freely available software.  A study by the Information Commissioner’s Office found everything from bank statements to scanned passports on hard drives bought online and at computer fairs.  Criminals use old hard drives as a source of personal information to commit identity theft.

So how do you securely delete your files?  There are a number of free, simple options.  If you want to do the whole disk, my personal preference is Darik’s Boot and Nuke (DBAN), just download and burn onto a CD, boot from the CD and away you go (obviously be very careful you don’t remove anything you want to keep).

If you have a Mac, you can use the built-in Disk Utility (under /Applications/Utilities).  And if you want to do individual files, give Eraser (for Windows) a try.  On a Mac, delete the file and then select Secure Empty Trash to permanently remove.

What about if your drive has failed?  Well people can still get the files off by extracting the platters, though it’s much harder work.  You can use a hammer and some heavy blows or a drill to damage it beyond repair.

It’s not difficult to ensure your data stays safe, just remember to take the right precautions.