h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Anyone updating a PC or monkeying around with PC parts will soon find out that there are two forms of hardware based option settings, these are dip switches and little jumpers that go over pins.

I prefare dips, no messing about with tweasers or figuring if the jumper is the right size for the pins. but not many PC related devices come with dips because there more expensive to build into a device. if you do come across them there more likly to be on motherboards for things like duel bios and memory or bus speed settings.

-- DoctorMO --

Dips are for posh people. If you find one, you're lucky, or you;re actually working on a hi-fi and not a computer at all. However, jumpers are pretty basic and easy to use. If you lose the top bit, you can pinch another one from an old peripheral, or, if desperate, use a little bit of tinfoi'. Not recommended, but it does work. Don't forget, if you want to take off the jumper cap and have no cap at all, keep it handy by putting it 'hanging off' with just one leg in, so you can use it again. If this is no good (eg there isnt room), attach it to a nearby surface with a bit of sellotape. Whatever you do, don't take it out and hope you'll remember what you did with it when you need it in 18 months time.

*Really* posh motherboards are all jumperless/soft-switching these days, where you set everything from the BIOS screen.

Before you fit a jumper, always look inside it. No, I'm not worried about microscopic mole mice nesting in them (they can take their chances! ) but just to check there's actually some metal in there! A few years back I thought I had a faulty HDD controller because no combination of master/slave seemed to work properly. I had all the drive links in the right places, it was just that (much) later I spotted that one of them was only a plastic cap; the metal insert had fallen out...

Oh, another tip... If you need a full-size jumper, a great source is any case with a front panel "speed" display. Assuming you're not unlucky enough to be running your machine at 888 MHz, there will be a spare jumper for every position on the display that isn't currently illuminated. Sometimes you can be *really* lucky, and find one with the expensive jumpers on it - the ones with long, thin plastic strips sticking up to let you grip them easily when you're manipulating them. In those circumstances I suggest you steal 'em all ( ) and replace the ones in use with standard ones. The "tagged" jumpers are great to carry about in your wallet, where you can amaze people in stressful situations by fitting them without the aid of pliers!

Oh, and if you're scrapping an old case, grab a couple of those flying leads used for the LEDs on the front panel - you know, the ones with the two-pin plugs that fit like a jumper? You take the LED off and solder on a small switch instead, thus giving you a tool that lets you try a jumper "on" or "off" without taking the machine apart in between. The three pin "turbo" headers usually have a suitable change-over switch already attached. It's useful for things like figuring whether your SCSI termination power needs to be on or off when you have an external drive fitted, or whether your CPU can cope with an extra step of overclocking...

I tried to fit a jumper last night - but my wife kept hitting me when I looked for the metal bit inside...

(, had to )

Other than that, some quite handy advice! I *know* I have a wee plastic zip bag with a few jumpers ... ... ... somewhere

How odd.