Helping my son revise for a maths test .. most of the questions seemed a bit dull and unlikely to catch a boy's imagination, so I made this one up for him.

A crazy sniper shoots a high velocity bullet vertically upwards.  The muzzle exit velocity was previously measured on a firing range, using an accurate timing device, to be 980m/s.

Use the simple equations of motion (known as the SUVAT Equations .. available on thickipedia here) to calculate

A) the time the bullet takes to reach the top of its trajectory
B) how high it goes
C) bonus mark : could the gun have shot a hole through the Red Bull Stratos balloon just before Felix jumped?

Sony Vaio VPCF13M0E - CPU heatsink clean and re-fit

My work laptop (a Sony Vaio VPCF13M0E) had become very noisy, with the fan running full speed as soon as it did any actual work.  A bit of googling found that this was a common problem.  The original heatsink paste becomes dried up, and doesn't conduct heat well.

Here's some pictures of the steps I took to fix it.  Obviously ONLY ATTEMPT THIS if you know what you're doing, and the machine is out of warranty.

Time taken: 2 to 3 hours total. 
You will need:

• Small cross-head screwdriver
• Anti-static wrist strap
• Heatsink paste
• Methylated spirits
• Cotton buds, kitchen roll
• Somewhere safe to put all those tiny screws - I recommend a large blank sheet of paper (with a drawing of the back of the machine) to put the screws down onto

1.  Remove the battery, and all the screws on the back plate.  Keep careful note (with a drawing of the back of the machine) where all the screws go.  There are several different kinds, and a few little tricks.

Remove the screws - on the back
- inside the battery compartment
- near the battery connector
- covering the RAM (middle plate)
- covering the hard disk (lower left)
- holding the hard disk in.

The optical disk drive can be pulled out of the machine, revealing three small screws (on the left).

I counted 24 screws in total.

Next is the tricky bit.  The plastic back plate can be gently lifted off, taking care to not stress the USB, SATA, ethernet and VGA sockets on the right of this picture.  Nearly there!

2.  Wear an anti-static wrist-strap for this next stage.  You can see mine is clipped onto the metal part lower-right.

The CPU and GPU heatpipe plates are held on by springy metal strips and four screws each.  Take these off and keep them separately.  Remove the small fan connector from the motherboard.

Once it's free to move, ease the plates away very gently from the top of the CPU and GPU chips.  Some dried paste will be left behind on each one.

3.  Clean all the old grey gunk off the plates with cotton buds and methylated spirit.  Very carefully clean around the CPU and GPU chips with cotton buds/meths, making sure not to damage any of the small surface-mount components.

4.  Examine the state of the heatpipe.  There should be no leaks or other damage.

I found that the copper heat plates that go onto the CPU and GPU, were not very flat!  You can see the ridge marks where it has a concave bit.

A bit of work with a diamond file got them to be much flatter (this picture was taken about half way through the flatting work). Only do this if you are confident and skilful with this kind of work; you should still get OK but not ideal results if you just clean (but don't flatten) the heat plate.

Take care not to remove too much material!  Keep cleaning both the file and the work with methylated spirit to avoid build-up of copper particles that could leave deep scratches.

4. Finally you should have everything clean and ready to put back together.

Apply a thin coat of good quality heatsink compound (I used Arctic Silver).  The amount I've put on here is plenty - any more will just get squeezed out and be wasted.

5.  I gave the heat plate springs a gentle tweak to make sure they were pushing the plates down. I also gently cleaned the fan blades with a paint brush and hoover to remove dust.  There wasn't much dust build-up on the actual heat sink blades.

6.  Re-fit the heatpipe carefully.  It's best to work slowly and fit screws in diagonal opposites i.e.

1  4
3  2

7. Fit the back of the laptop back on, and re-fit all the parts and screws.


8.  Finally - proof that it's definitely worked is that your laptop should run quieter and better.  If you want to give it a good workout, I would recommend downloading and running some Cosmology@home tasks.

You can see with all CPUs running at 100%, the cores are at a max. of 68C which is fine.

-- END

SATA drives and Acer T135

More on the SATA / Acer T135 saga.

Having got the PC to "see" the drive in the BIOS, it should be a simple matter of restoring the system volume onto this drive (or cloning it from the old drive), making it a primary, active partition (so it's bootable into Windows), and off we go, yes?

So I created 1 large partition for the system and restored onto it. Did this work? No. Not in these Acer machines.

According to boot.ini (which the wonderful StorageCraft ShadowProtect software can read easily), partition 2 was set as the boot volume. And I only had 1 partition - so better change it.
So I edited it to be partition 1, and tried again. No luck.

I recall that the machine was supplied with the drive having two partitions -

• Partition 1, around 2.8 Gbytes, for automatic 'recovery' of the machine
• Parition 2, the usual Windows system volume.

The recovery process is an Acer thing. Basically on boot, you hold down a key (Alt+F10) and the machine goes into auto-recovery mode. This basically re-initialises the system partition (2) from a factory-created archive held on partition 1. That's what the 2.8 Gbytes is used for. It provides a degree of safety for uses who trash up their machines so they won't boot, and I suppose it's cheaper than supplying Windows installation media.

I'm not a great fan of this kind of auto-recovery (after all, it will trash all your programs and data, for sake of getting Windows re-installed). I prefer to use StorageCraft ShadowProtect with an external USB drive, as then I can get the machine back exactly to "how it was" the last time backed up.

Out of a mix of desperation and curiosity, I tried holding down Alt+F10 as the machine booted (off the new disk, which did not have any recovery software on it, only a clean system image). Voila! it booted into Windows, off my new partition 1. So this told me two things:

1. I could restore the machine, somehow.
2. The Acer BIOS somehow seems to be ignoring boot.ini, and doing its own thing, based on this Alt+F10 key (or lack of it).
3. The Alt+F10 key forces a boot from partition 1. It works, but it's a bit inconvenient for everyday use.

Another attempt

Now knowing this about the Acer machine, I tried again, but this time

• Small initial partition (around 2.8 GB), which I put a copy of the Acer restore stuff onto from the original disk
• Large system partition (the rest of the disk) for Windows etc.
  

The first was copied from the original Acer-supplied hard disk. The second came from my ShadowProtect backup.

Still no luck. It would not boot into Windows. But with Alt+F10 held down, it would boot into the Acer Recovery software on Partition 1.

Yet Another Attempt
Finally, in desperation - I thought - why not run this Acer recovery software, and at least see if it can make the machine (normally) bootable, off a freshly restored partition 2. So I let it restore, effectively over-writing partition 2 with its virgin install of Windows + the Acer utilities etc. that came with the machine. (No CD-ROMs are supplied as standard).

This resulted in a machine that actually boots up (although missing a lot of stuff, obviously). So - here's the trick - that Acer Restore feature is actually necessary for a machine rebuild - in a totally non-obvious way. boot.ini looked just the same, before and after the restore.

I wonder what the Acer Restore does to the disk. It does some magic that is not obvious.

So ... having proved that was possible, I then restored the ShadowProtect image back over partition 2. And that finally worked! I had a machine that booted normally, and had everything back where we wanted it.

I still don't know why the machine is so fickle with its boot-up, and why it ignores Windows' own boot.ini.

Conclusions

• If you have an Acer T135, that 2.8G of "stuff" on the Restore partition is essential to the continued use of the machine, if you replace hard disks. Don't just think that having valid Windows install media and a valid key will be enough to get you out of trouble.
  
• Acer T135 has its own boot control which ignores Windows.
• Don't forget to jumper new SATA drives down to the older standard, if they can be detected.

and finally

• Don't buy machines with proprietary motherboards and BIOSs if you can help it! Sooner or later they will drive you mad.

Recommended tools and parts for this kind of work:

• Patience
• Anti-static wrist strap
• Screws for holding the new drive in
• SATA cable (usually not supplied with 'OEM' drive packages)
• Jumper (again, usually not supplied)
• Tweezers for fitting the jumper
• Partitioning / formatting / backup / restore software, such as Norton Ghost, Acronis TrueImage, Partition Magic. My personal favourite at the moment is Shadowcraft StorageProtect 3.2 which works fast and well in my experience. It comes with a bootable CD-ROM image that means you can work with machines even when the hard disks are unbootable. Review of the software here
  

Acer T135 with and new SATA drives - a snag

Just came across a nasty little snag with SATA disk drives. I thought I'd write it up, in case you run into something similar.

One of our family computers is an Acer Aspire T135, around 3 years old now. The 80GB hard drive is getting rather full and slow. Time for an upgrade.

Step 1 - check what the existing PC can do.
It has a spare SATA connection on the motherboard, so that seems like the best way to go.
There is plenty of space in the case for a new drive.
There is a spare SATA-compatible power connector (different to the old-style 4-pin Molex's) dangling in the case.
I'll need to get a new SATA data cable for the drive.

Step 2 - plan how to use the drive
My initial thought is to use the new drive for the OS and programs, and the old drive as scratch area and - if it makes things run faster - the windows swap file.

Step 3 - choose a drive
A quick look at drive specs etc. suggests a 500GB drive as the best price point at the moment (given that the machine does not have to handle huge amounts of data usually).

A quick check on the Acer website suggests no particular compatibility requirements for second drives (then again, it doesn't really say a lot about their machines anyway).

Western Digital do a nice looking "Green Power" model which claims to save power. As family PCs get left on all the time, that seems like a good idea.

I got mine from Novatech as they are local (www.novatech.co.uk).

Step 4 - install the drive
Short work with a screwdriver and the new drive was ready to run.
Boot up, check in the BIOS that the drive was recognised ... nothing, only the existing drive is found.

I tried various things, including:

• Swap the existing and new drive data cables
• Swap the existing and new drive power cables
• Try with another SATA drive I had available (an older 160GB Maxtor). Ah-ha! That works!

So why does the new drive not work?

Step 5 - fault-finding .. it's NOT the BIOS ...

• Maybe the BIOS is too old to read 500GB disks. So I flashed the BIOS with a newer version, directly from Gigabyte's website, rather than from Acer's website.
• The motherboard is a K8VM800. But it's labelled as the K8VM800MAE on the motherboard itself. Gigabyte list two versions - Rev. 1 and Rev. 2 - but nothing about the MAE. According to the chips fitted it's closest to Rev. 1. (looking at the Ethernet chip type).
  
• Incidentally, flashing BIOSs on computers like the Acer T135 that lack a floppy drive is somewhat time-consuming and troublesome. It hasa nice integrated flash card reader though ... so ... After a bit of Googling, and making a DOS-bootable disk on a Flash SD card, which worked fine on one of my other machines, I gave up, yanked a floppy drive out of another machine, and used that instead ...
• It flashed OK (but with a warning message), and it ran the computer OK, but it kept giving checksum errors on startup. Not such a good idea. Revert back to the original BIOS (which I had kept).

Step 6 - try another 500GB drive

As it happens, I have a 500GB SATA drive (different brand - Samsung) in another machine. So - let's try that.
It works! So there isn't a capacity issue. Must be something weird with the drive.

Step 7 - has anyone else hit this before?
After some tricky Googling to avoid the hundreds of old review articles on T135's, many that have a different spec, I found a forum that suggested that:

• SATA has different speeds - 150MB/sec and 300 MB/sec
• While everything is supposed to auto-adjust, it might not

A quick check on the drive manufacturer's website pulls up a datasheet, and -- guess what -- there are some jumpers to force the drive down to the slower speed.

http://wdc.custhelp.com/cgi-bin/wdc.cfg/php/enduser/std_adp.php?p_faqid=1679

It's that OPT1 jumper (pins 5-6 on the drive family I'm using).

Now the BIOS sees the drive. But the original drive seems to be taking ages to boot up in to Windows (despite not being changed at all). More on this tomorrow.

Happy Solstice (yeah, right).

I received a "Happy Solstice" message from someone close to me. While wishing them no ill whatsoever, I felt like sharing my own thoughts on the matter.

As a fan of Western reductionist scientific principles I was drawn to musing on the possible reason why the sun might not 'rise'. I came up with:

1. The sun stopped shining.

2. A large, opaque extra-terrestrial object (such as an Arcturan Mega-Goat) suddenly parked its hairy ass somewhere between the Sun and Earth.

3. The Earth stopped spinning.

Other than that, well, yup, the Sun will generally rise as usual.

On (1) - the bad news is, this will happen sooner or later. But there's probably a billion years to go. As the Sun runs out of hydrogen fuel and starts to consume heavier elements, the most popular scenario is that it will gradually expand and swallow all the inner planets (including Earth). Bummer.

On (2) - many of your friends who have chemically prepared for the Solstice might worry about this. Goats are usually friendly, but are omnivores and have large appetites. I would recommend further research to establish whether goats prefer red planets to greeny bluey ones.

On (3) - Newton's Laws suggest that if, for some reason, the earth did suddenly stop rotating (and therefore the Sun not rise one morning), you would most certainly know about it, even if you were in bed at the time:

• Earth rotates Eastwards (i.e. towards the "rising" sun) at approx. 1000 miles per hour at the Equator. About 600 miles per hour at European latitudes.
• You are rotating at the same speed, snug in your bed.
• Earth stops. (This is unlikely as it would require a huge force to be applied to something that's very large, very heavy, and basically 99% molten rock so quite squishy and hard to get hold of). A large meteorite might just do it.
• You, your bed, your house, and everything else that's not tied down initially keeps on moving at 600 miles per hour to the East.

This is likely to be quite noisy and uncomfortable, and so people would (briefly) wake up.

You can therefore banish any lingering spiritual guilt you may feel if you are not standing in some damp field with other beardy weirdies, swaying and singing out of tune.

I suggest that you pass this tip on to your earthy friends, so that they don't have to get out of bed each year specially just to check. On the other hand it's mostly harmless and probably quite good fun, and you might even get lucky afterwards ...

I've been playing about with KPL (Kids' Programming Language), my first little program is a Celestial Mechanics simulator - try it out here.

Caffeine

Have a large RFI (Request for Information ) document to fill in answers to this week. Once the phone stops ringing I find that I can get 'into flow' and work more effectively on these things. But that needs strong and regular caffeine input.

A couple of weeks ago I downloaded some cool software that generates 3D models of molecules. The idea was to encourage Hannah to learn a bit more about chemistry, although I played with it more than she did.

Here's a caffeine molecule model. The software is free, and there are lots of models out there on the Internet as well. I'll post links to them shortly.