Atomic I/O letters column #17
Originally published in Atomic: Maximum Power Computing Reprinted here 31-Jan-2003.Last modified 16-Jan-2015.
Sticky question
How can I bond/connect a frame onto the side panel of my computer case without using rivets or any protruding objects which may mar the finish of the exterior of the panel? Epoxy is the only solution that springs to mind. The metals bonded are aluminium (frame) and mild steel (side panel - 1.6mm thick). I read on the side of my epoxy packet that the stuff loses its cohesive properties at temperatures exceeding 60ºC. Can you recommend any stronger compound which does not have thermal limitations and is suitable for those metals?
Related information: The frame will house a radiator which will be oil-filled for cooling two CPUs. The radiator dimensions are 18cm x 25cm x 4cm, it will contain oil, and thus I estimate that the weight of it will be about 1.5kgs.
Felipe
Answer:
Use metal-filled epoxy. People fix engine-blocks with the stuff. It comes
in five minute bond versions, as well.
Call around your local hardware stores and tell them you're looking for Devcon aluminium-filled epoxy. There are other brands, but Devcon is the Kleenex of metal-filled epoxies.
And yes, because it's metal-filled, it's quite thermally conductive. So you can use it to stick heat sinks onto things. Cut it with some thermal grease if you think you're ever going to want to remove the heat sink again.
Scuff up the bonding surfaces with the coarse abrasive paper of your choice, and then thoroughly clean them with meths or something before you apply the glue, and you'll probably find the resultant joint to be stronger than the riveted ones in your case.
Stolen memory?
I'm running Windows 2000 on a 233MHz Pentium II MMX, with 64Mb of RAM. I won't mention any of the other stuff, so you guys get a chance to catch your breath back and recover from your fits of laughter.
I understand about how the swap file works in conjunction with RAM, but what I can't understand is the report Windows Task Manager gives me on the current memory usage. It says I'm using 137128K out of a total 181384K, and my swap file is about 126Mb, so that sounds about accurate as a maximum. But I added up the total for the currently running processes and got a total of 26320K usage.
Could there be a bug or some kind of spyware stealing my extra memory?
Daniel
Answer:
Win2000 on a 64Mb box. Woo. How's the weather over there in Drive-Flog Land?
Your memory usage puzzle, though, is simple enough. If you look at the Performance tab in Task Manager, you'll see a buttload (a technical term) of memory being used for caching.
Back in the Win98 days, Windows' disk cache handling was quite lousy. These days, it's pretty good. It uses lots of memory for the disk cache, but that generally works out OK. And that's where your RAM's gone; Windows versions from Win2000 onwards are more and more aggressive about using empty RAM to accelerate disk performance.
This results in alarmingly low "free" memory and alarmingly high "used" memory, even when pretty much nothing is running. Windows will drop the cache and give your RAM something better to do as soon as you need it, though.
(I'm giving this page a little polish in late 2008. Windows Vista has been out for almost two years now, and it's famous for eating almost all of the system RAM no matter what you're doing. That, though, is not a problem. Vista has problems, but cache-RAM is not one of them. )
You could still do with some more memory, though. Another 128Mb, at least, would make a big difference to your system performance.
Choking PC
I have a problem with a startup file that I want to delete. The file is "choke.exe -blahhh". I ran msconfig.exe to disable it on startup. After I apply the setting to take it off, it tells me to restart my computer, so I do that and when it reloads again it tells me to run in normal so it can undo what I just did. I can't find the choke.exe file on my computer to delete it. How can I delete this file?
Dean
Answer:
You've got a virus - a worm, actually. W32.Choke.Worm isn't, however, a
serious problem. See
here for removal instructions.
Silence!
Can I link my LaCie 60GB PocketDrive to a Yamaha AP-U70 PC Amplifier via USB?
I intend to play my MP3s (stored in the LaCie) through the amplifier without switching on the PC or connecting through it. The AP-U70 is said to handle any external device that has USB connectivity. Basically, I want to use the PocketDrive as an MP3 player. The PC's fans are far too noisy.
Eli
Answer:
Sorry, no can do. You can't connect USB peripherals to each other, only
to USB controllers - optionally, via hubs or other repeaters.
(2008 update - Some devices now support USB "Host Mode", which lets you hook up things-other-than-computers to each other. Host Mode still hasn't really taken off, though; generally speaking, even battery-powered things with a USB port are unlikely to be able to connect directly to other USB devices.)
If you want a stand-alone MP3 player, you're going to have to, well, buy one. The AP-U70 has analogue inputs as well as its USB connection, so you can hook it up to any MP3 player, or other ordinary analogue stereo sound source.
Alternatively, you could try reducing the noise your PC makes by installing quieter fans or slowing down the ones that it has, putting sound absorbent material on the panels, and so on.
Or you could buy active USB extension cables (basically a one port hub built into a cable), which'll allow you to put the AP-U70 further away from the computer. The maximum length for a USB cable between hubs, or for a single active extension cable, is five metres. Since you can chain up to five hubs or active extension cables from a root port, that gives you a maximum range of 30 metres. Going to the full 30 metres will cost you more than $AU200 in hubs and/or cables, though!
Parallel paralysis
Why does my somewhat tweaked, usually mildly quick WinXP Pro/Athlon XP 1800+/512Mb PC2100/Epox 8KHA+/GeForce3 beige box run like a complete slug whenever I print anything to my (admittedly rather ancient) parallel Lexmark LXK3000 colour printer?
I'll define slug: Whilst printing anything, the entire system crawls to a (near) halt, with tens of seconds of lag between USB mouse input and any corresponding action onscreen. Only happens whilst printing and it's annoying the bejesus out of me.
Is it cos the PC is connected to a patriarchal parallel printer? Are my simplistic settings slightly silly? Is it due to languid LAN lag? Is the beige box buggered? Aaaargh!
Brad
Answer:
This is the way of the parallel port, Grasshopper.
The bad news: You're not going to be able to stop your computer from going into Cold Treacle Mode when there's lots of data being transferred via the parallel port.
The good news: You may be able to reduce the amount of time your computer spends being slow and annoying for a given print job, by switching the parallel port to a faster mode.
By default, your printer port may be in ancient unidirectional Standard Parallel Port (SPP) mode, or in the slightly less ancient but still slow Bidirectional Parallel Port (BPP) mode. Both of these modes are good for only about a third of a megabyte per second, at best. Every PC motherboard for quite a long time now has supported the faster Enhanced Parallel Port and Enhanced Capabilities Port (EPP and ECP) modes, good for peak speeds of two megabytes per second.
Go into your BIOS setup utility (probably by pressing Delete when prompted at the start of the boot process), hunt up the parallel-port mode setting, and see if it's SPP or BPP. If it is, select EPP instead. You can use ECP if you like, but that needs a DMA channel, and EPP doesn't.
All of this will be pointless, of course, if the limiting factor is how fast your elderly printer can accept data.
Cable hacking
I'm sure you know that rounded IDE cables come with two device connectors. In an IDE RAID setup, I only need one device per IDE cable. Is it okay to simply cut off the second connector?
David
Answer:
Yes, it's fine. Make sure that you don't end up with bare wires sticking
out of the cut portion and touching each other, of course. Also make sure
you cut off the second drive connector, and not the motherboard connector;
otherwise your cable may be too short.
80-wire IDE cables should be at least 254mm, ten inches, in length.
Power plug perplexity
I'm soon going to get a Lian Li PC-60 case, and I'm looking for a good PSU. I like the look and power of the Topower 420 watt PSU, but when I looked at your review, it seemed that the PSU only had one plug in the back, obviously used to connect the PSU to the power point. My current PSU is only 230 watt, but it has a plug in the back for a monitor. If I get the 420 watt PSU, do I need to get a special cable to connect my monitor to the power point?
Jonathan
The two standard flavours of IEC power lead.
Answer:
No. Just get an ordinary IEC lead - three-pin mains plug to three-pin IEC
female socket. Which lead, by the way, is known to older and crustier appliance-botherers
as a "jug plug", because electric jugs were among the first devices to use
IEC connectors for power.
The extra male IEC sockets on the back of some PSUs are just a convenience feature. They're switched with the PSU (or they ought to be, at least), so they let you turn on a monitor at the same time as a PC, saving one push of a button and one power point. There's nothing special about the power they deliver, though. A plain old IEC power lead is all you need.
Doesn't add up
I recently downloaded 3DMark2001SE and looked at the System Info details for my GeForce2 MX graphics card. Total Local Video Memory and Total Local Texture Memory are both 64Mb, but the Total AGP Memory is 32Mb. Shouldn't it be 64mb too?
Dean
AGP memory numbers may or may not be informative.
Answer:
The "total AGP memory" value in system info programs may be equal to the
physical memory on your graphics card plus whatever AGP aperture value is
set in your computer's BIOS, or it may just be the aperture value by itself.
The aperture value determines how much of your system memory can be used
for AGP texturing, if necessary.
You won't, however, necessarily see the right number when you look at the info display in 3DMark, or in other utilities like Nvidia's AGP memory display application (find that here). Your AGP aperture probably is set to 64Mb, but graphics card drivers often can't figure out the right value, and deliver some semi-random number. Sometimes the reported value is zero bytes.
Don't worry about it, though. If it's wrong, it's just a cosmetic problem.
Plug wrangling
I use a normal microphone (3.5mm socket) headset to dictate to my computer; I have it plugged into the back of my Creative sound card. However, I need to be able to use my computer as a telephone by using my external voice/speakerphone modem.
The modem has a microphone and speaker jack on it. How do I set the system up so that I can talk to the computer but also talk through the modem? Do I have to split the microphone cable and input it into both the modem and soundcard, or can windows (XP) be set up to send the voice to the modem automatically?
The same would apply to the speakers also - how do I get the sound from the modem into my headset speakers as well as be able to receive the computer sounds for music?
At the moment, whenever I want to call someone, I have to pull the microphone and headphone plugs out of the back of my computer and plug them into the modem, and then when I've finished, I have to plug them back into the back of the computer.
Heath
Answer:
One solution to this problem is to use a switchbox. Assuming you've got
a stereo headset and a mono mic, you need to switch three two-wire connections.
The ideal gadget for doing this is a "TV game selector" switchbox, which
is meant to connect to composite video and stereo audio input from two game
consoles or similar devices, and select which one's connected to a TV. These
boxes just switch three RCA connectors, though, so you can use the video
connector for the mic and the audio pair for the 'phones. You'll need a
few plug adapters and RCA-to-1/8th-inch Y-cables to connect everything,
but it's doable.
The switchbox itself should cost you less than $AU20; the one sold by Jaycar here in Australia, for instance, is catalogue number AC-1668 and costs $AU14.95.
Alternatively, you might be able to rig up a computer-based system, but frankly I doubt it. Your sound hardware might have enough ins and outs; many current sound cards and built-in-sound motherboards have internal auxiliary input connectors, including one that's actually meant for modem sound. But you'll be shuffling mixer sliders every time you want to make the switch, if it turns out to be possible at all.
I'd use the switchbox.
4X! 4X! 4X, damn you!
I have a Hercules GeForce2 MX 400 on an ASUS CUSL2-C motherboard with a 1GHz Pentium III. The CUSL2-C is supposed to support AGP 4X. In the BIOS I set it to 4X. But in Windows XP it says it's running at 2X, in my nVidia driver settings under Hardware Options. When I try to set it higher, 2X is the highest it will go. Some people I talked to said to find a 4X registry patch, and someone else told me to update the motherboard BIOS to version 1007 because he said that 1009 didn't work, but nothing helps. I just want to enable 4X AGP. Any help would be appreciated!
Teejay
If your motherboard can only do AGP 2X, don't sweat it.
Answer:
Apparently, the CUSL2-C will only do AGP 2X if you're running an FSB above
140MHz. Abstruse BIOS changes or tweak programs may be able to get past
this, but the limitation is a sensible enough decision on Asus' part. Locking
AGP down to 2X when this poor little i815 chipset board's AGP bus is substantially
overclocked greatly increases the probability of AGP continuing to, you
know, work.
If you're not running above 140MHz FSB, I don't know why AGP 4X isn't working.
Fortunately, though, it utterly doesn't matter.
The only time you'll notice much of a performance difference between AGP 4X and 2X, and the original 1X and the new 8X for that matter, is when you've used up all of your video card's own texture memory and the PC therefore has to use system memory for textures. This "AGP texturing" will cause your 3D frame rate to suddenly suck very very hard (in the case of AGP 1X), or very hard (for AGP 2X), or merely quite hard (for AGP 4X). Even AGP 8X texturing isn't a good performer compared with on-board graphics card memory.
If you're not doing AGP texturing, the difference in performance between all of the different flavours of AGP, and even between AGP and PCI (which can be thought of as "AGP 0.5X minus a fairly large amount"), is small to negligible. It doesn't hurt to use one of the faster modes, but there's not much to be gained.
So don't worry about it. Just use the computer.
