Look out! Simulated explosion effect! Lucky for you, it was only your computer that got toasted – that’ll teach you to eat cornflakes and milk out of your PSU. Tisk, tisk, says Daniel Rutter, who’s on the scene with tweezers and an MX700 cordless mouse for IOOTM. Electrifying!
IOOTM: Inverter emanations
I: I was once told that fluorescent lighting should be avoided for network cable pathways, because of the interference that it generates. This made me curious about the interference created by fluorescent case lights, especially with the proximity of IDE cables and motherboard buses.
I know that normal fluorescent lights are much larger than CCFLs, but then case lighting is in a smaller space with metal walls designed to keep interference out (in this case, keeping it in). Is data corruption a consideration with case lighting?Phil Choo
O: Indeed network cables should be kept away from fluoro light battens and electrical cables, and certainly not run parallel to them. If a network cable in the ceiling has to cross a batten or cable, it should do so at right angles, to minimise interference. Network cables should also be strung as far above interference sources as is possible.
You'll generally, actually, get away with draping network cables over a batten or three, any way you like. But it's best to assume that the battens pump out a lot of noise and that the nodes at either end of the cable are particularly intolerant of it, and do what you can to minimise interference, simply because it's likely to be such a pain to re-pull the cable if this does in fact turn out to be the case.
PC cases are earthed, and sink radio frequency interference (RFI) to ground, so RFI sources inside don't just bounce their energy around within the box. If the earth is lousy then this won't happen, and it won't happen at all if you've got a stylin' modded case made of wood or plastic or something, but generally speaking, the metalwork inside a PC soaks up the RFI that hits it.
Despite this, you'd think that sticking CCFL gear next to data leads would cause problems, but in practice, it doesn't. Cold cathode fluoros, their supply wires and their inverters are a significant RFI source, but it turns out that all the measures modern PCs have to protect them from their own interference also quite effectively protect them from interference from other sources. Up to, but not including, the geek next door and his converted-microwave-oven HERF gun.
Samsonite computing
I: My mate is putting a PC in a suitcase, but his video card is too tall.Is it possible to make a right-angled adaptor for an NVIDIA Ti4400 video card that will work?Russell Farley
O: Make? Well, in theory, yes, but you'd do better to buy one.Right-angle AGP (and PCI) adaptors exist, and aren't very expensive, though your local computer store probably doesn't have them. They're used in one and two unit rack cases (which aren't tall enough to accommodate normal cards vertically), and may even support AGP 8x.
Not that that matters a lot; if you end up having to use a slower AGP mode (assuming the card and mobo your friend is using both support 8x in the first place), you won't sacrifice any noticeable performance.
Finding such an adaptor without ordering it in from overseas is the tricky part. AGP riser cards aren't in a whole lot of demand among server builders, so they're thin on the ground. Server boards these days often have integrated video, and the ones that don't have it often still don't have an AGP slot.
Imaginary overclocking
I: I have an ASUS A7N266-VM motherboard and a XP2200+, which is achieving the AMD specified speed of 1,795MHz. The ASUS board comes with a 'PC Probe' utility that says the CPU is running at the minimum speed of 1,800MHz, but can achieve a maximum of 2,000MHz.
What can I do to get this speed? Is this utility just yanking my chain?Stuart Coulson
O: What you can do, is change your motherboard.The non-'VM', full-ATX version of the A7N266 allows basic frontside bus (FSB) overclocking via the usual software configuration in the BIOS setup, but I don't think any BIOS version for the micro-ATX A7N266-VM allows FSB tweaking. You're stuck with either 100 or 133MHz, pre-doubling, set with jumpers on the board.
The ASUS utility is basically just guessing about the overclock that's possible (on a board that allows overclocking at all. . .), and its guess is a conservative one. Winding up an 1800MHz-ish CPU to 2GHz is only an 11% overclock, which many CPUs can manage without even increasing the core voltage. Practically any CPU can be overclocked by about 10%.
On the minus side, an 11% CPU overclock is unlikely to give you a noticeable performance improvement for any real world task. It's nice to have if it doesn't hurt system stability, but it really doesn't matter much.
The new hotness
I: Why do motherboards contain so much legacy stuff? I mean, look at how big motherboards are, they are huge! I want smaller, fully-featured and non-integrated motherboards. Look at those huge 64-bit PCI slots. (What people do for backwards compatibility. . .)
Can I have my mouse now?Michael
O: Note: Asking for the IO Of The Month prize in your letter is considered impertinent, unless negotiable securities and/or premium beverages are also provided for the judges' consideration.
And now, on with the answer.
What 'legacy' means depends on who you ask. ISA slots, yes, but serial and parallel ports generally count as 'legacy' as well; 'legacy free' motherboards have extra USB, FireWire and digital audio ports in their back panel connector block in place of the old nine and 25-pin D- sockets.
A full list of legacy interfaces also includes PS/2 mouse and keyboard connectors and the floppy disk controller, though, plus less important stuff like the gameport and Infrared Data Association (IrDA) interface.
PS/2 ports are proving hard to kill, and so are good old 36-wire ribbon-cabled floppies.There are a few reasons why the old interfaces keep popping up. One reason is that people want them; they want to be able to plug in their old parallel printer or serial modem or PS/2 keyboard or what-have-you without buying a USB-to-whatever adaptor.
Another reason is that half of the interface to connect these things is still built into modern chipsets. Modern motherboards don't have an ISA bus any more, but their peripheral bus controller ('Southbridge') chips still have a Low Pin Count (LPC) interface built in. LPC is what replaced ISA for connections to the Super I/O chips that are used for all of the legacy stuff -- and which may do fan and temperature monitoring, too. The incremental cost to the motherboard manufacturers for including the legacy interfaces isn't large.If you ask for a 'fully-featured' motherboard, you're asking for a board that has all of those old legacy interfaces. They are features, after all.
There are plenty of micro-ATX and smaller boards around these days, though, which may suit you. There are tiny 'Small Form Factor' boards that fit in toaster-sized cases but can accept high-end CPUs and an AGP graphics card, and there are cheaper boards, just as small, that use low-power VIA CPUs and are still adequate for less demanding tasks.
Yes, all of these boards still have a floppy drive connector on them, and probably PS/2 and serial and parallel ports, too. But you don't have to [i]use[/i] them.
Double-adapted audio
I: After seeing Atomic's review of the Logitech Z-680 speaker
Issue: 137 | June, 2012