Thermophysics, the experiment 1

Monday 18. August, 2008

Today I had a measurement to do in our university’s physics student laboratory. I had a kettle full of water of 80 degrees Celsius, an aluminium rod and a smaller pot of room temperature water.

The idea was to conduct heat from the bottom of the hot kettle through the rod to the pot. I had temperature sensor in both the upper and the lower end of the rod and in the little pot. The temperatures were read to a computer running some Matlab-script. I was supposed to measure the temperatures for 10 minutes with 1 minute intervals and write them down (It cleary would have been too little work for us if the script had had a for-loop to do this too).

So, for ten minutes I wrote the results down and changed in a copper rod and did the same things to it too. In half way of the second measurement set, my instructor took a look on the first results and was a bit puzzled.

Somehow the upper end of the rod heated as expected, the water in the pot heated as well. But the temperature of the lower end of the rod got lower! How is this possible?

(this is an “I want comments”-post and the real answer to the question above will be revealed later, unless someone finds it out. >:-) )

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Go get some Wine 1.0

Thursday 19. June, 2008

Wine 1.0. It’s out, now be a nice little nerd and go get it and no one gets hurt.

You might want to get the Firefox 3.0 while you’re at it…

Maybe even run Firefox 3.0 in Wine 😮

In case someone doesn’t know where to get those: Wine and Firefox

Slacking once again

Monday 16. June, 2008

No, nothing to do with Slackware this time. For some reason I just don’t want to do anything. Just few days ago I entered my Prospekt Linux chroot environment and spent there less than 2 minutes and began to feel angry so then I just left to Firefox and StumbleUpon. Still haven’t stumbled upon on something I really want (secretly)… I guess I can’t get one from teh internet, which is scary 🙂

I did try to take look on the JPM sources again and then thought that I should have done it with Java as it has a friendly compiler telling me I’m doing something wrong with the data (structures), I guess sometimes dynamic data typing isn’t fun… or I’m doing something terribly wrong (quite likely, actually)…

On the other hand, you have different fingers. As school is out and has been for weeks actually and nothing better to do, I have been hanging around in our city’s market place or nearby my apartment with a friend. It’s almost weird, we just stand there for couple of hours talking about various stuff but mostly about computers. Weird or not, I has been really fun and different. It’s really nice to be outside for a change and “it is time better spent” than normally just sitting in front of a monitor.

We’ve been playing Synergy too and we are on the second round on the big map pack and desperately waiting for the Orange Box version so we could co-op through HL2 Episode Two.

Shopping for a new stuff

Monday 12. May, 2008

Today I kinda went shopping with my friend. I just got some urge to get a microphone for my computer so I could make weird voices and comments too while playing Synergy. There were few microphone models but I couldn’t decide so I went to look some keyboards and ended up buying a one too (Logitech Cordless Desktop EX110, comes with a mouse too) and then went back to the microphones and took one manufactored too by Logitech.

The keyboard seems to be better than the old one (Microsoft ComfortCurve 2000, which wasn’t that comfortable to me). The weird thing is that this Logitech-keyboard doesn’t have Scroll Lock-key and the Insert/Home/Pg U -keyset is a 3×2-keys not the ordinary 2×3-keys matrix, also they have moved the insert-key away from this set and put it in place of Scroll lock.

The microphone was a bit of disappointment but thats probably some driver problem. Currently I have to yell at the microphone to get Windows Sound Recorder to catch anything and the same goes to everything else too. If I turn on the mic boost, there’s a lot of background noise but I can record with my normal speaking voice, but the noise is unacceptable! Is this due to Asus P5N-E SLI motherboard and its drivers? I bet it would work in Linux >:-) This current situation means no funny voices on Synergy. God damn! Has anyone else had this same problem?

So Proud of Myself

Wednesday 9. April, 2008

Today I finally managed to repair my A-Link RR24AP(c) adsl-modem. The problem was that the wireless side didn’t function at all because the boot environment of the modem was corrupted. The corruption was my fault as I accidentaly used a wrong power source which wasn’t powerful enough, all I could see was the lan-connection light flickering.

Few weeks ago I contacted A-link’s tech support and they told me to send the modem to their technicians, but I didn’t bother to that as the warranty period had ended quite some time ago.

The modem accepts ssh-connections for controlling it and a linux shell/toolset, busybox. Boot environment configuration can be accessed through /proc/ticfg/env -file. A quick look into it and some knowledge from RouterTech’s forums and the modem’s system log revealed that WLAN_EEPROM-values were missing. I don’t know exactly what these values are but I do know that without them the wireless doesn’t work.

I found a recovery software through the same forums but the program didn’t start. I crashed immediately. I was very disappointed as it was my only hope. As I knew that I needed those WLAN_EEPROM-settings so it came to my mind to take a look on that program with a hex editor (Notepad++ with hex editing plugin, in case you want to know…) and indeed there they were! Apparently it was a template of the eeprom-settings, but still I got my hopes up again!

I didn’t expect this template to work directly which was then confirmed when I tried it. Again the answer was found in RouterTech’s forums. Some other guy had the same problem of missing/corrupted WLAN_EEPROMs and some other guy told him that WLAN_EEPROM8-line contains a hardware specific id in REVERSE order (12 34 56 would become 56 34 12). Modifying that line did the trick! The WLAN-led lit up! I had restored the right WLAN_EEPROMs (WLAN_EEPROM0-WLAN_EEPROM14) and I had a working wireless access point. One problem, though, the modem though that the BSSID was 00:00:00:00:00:00 THAT IS NOT RIGHT! (and only my laptop’s Intel 3945 detected it, my buffalo usb-wlan stick didn’t see anything).

And to the Google we went… it turned out that WLAN_HWADDR0 should be set and contain the MAC-address of the wlan-system.

Now the modem is under testing and seems to run just fine.

(I don’t publish the WLAN_EEPROM-values here because I don’t know if  that would be legal)

Incomplete standards

Saturday 5. April, 2008

My friend does some C programming and many times he has im’ed me about his progress in his projects or other interesting results. This time he complained that his code doesn’t work the same way in Linux as it does in Windows. I’ll demonstrate the problem with the same code he demonstrated the problem to me:

#include <stdio.h>

int main(int argc, char *argv[]) {
int temp = 0;
printf(“%d %d “, temp++, temp++);
printf(“%d\n”, temp);
return 0;
}

What do you expect this little program to do? Does it print something? You’re right but what exactly does it print? well, that depends on what compiler it was compiled on…

WIth University’s Sparc-Solaris gcc-3.0.4 it print 0 1 2, with Ubuntu Feisty’s gcc-4.1.2 and lcc-win32 it will print 1 0 2 and actually lcc-win32 printed the same as did Cygwin’s gcc-4.4.3.

Googling for explanation ended up telling that this case is not defined in standard C so results may vary on every compiler.

I wonder why that hasn’t been defined… For a programmer it should be quite clear that this code should print 0 1 2 but I do understand that this might get bit controversial as you could expect it to print anything from 0 0 1, 0 0 2, and so on to 0 1 2.

(Ha! You might have expected me to write about my lack of morality and standards instead of this…)

New Computer

Monday 3. March, 2008

I finally got around to buy me a new computer as the old one really started to feel old. Now I just have to cut in some “expenses” as it was rather pricey for a student budget.

This is what I had before:

  • AMD Athlon XP 2400+, 2.0 GHz processor
  • 1 GB RAM (DDR-333)
  • Asus A7V8X-X motherboard
  • 200 GB HD by Seagate
  • Geforce 6600 GT (AGP)
  • Some cheap DVD-drive that cannot read cd-rw-disks it burned
  • 1,44 MB floppy drive
  • 1,2 MB floppy drive  (I don’t really use it… It just looked cool)

Hmm.. funny… I don’t remember what components I had on it…
Anyway this is what I got now:

  • Intel Core 2 Duo E6750, 2.66 GHz
  • Asus P5N-E SLI motherboard
  • Corsair Twin2x  1 GB DDR2-800 memory kit, total 2 GB(TWIN2X2048-6400C4 G)
  • Western Digital Caviar SE16 320 GB HD
  • Gigabyte GV-NX88T256H graphics adapter based on NVIDIA 8800 GT
  • Antec Sonata III case with 500 W power supply

As I don’t have a car, I had a bit of problem on how to get it into my apartment from the local post office, but my two friends from the university helped with it. I don’t live too far from the office so we brought the three packages over by our bare hands 🙂

The case was the heaviest package and I had to carry it as far as the first traffic lights until my friend told me I looked ridiculous carrying the heavy big package so we switched and I got the lightest package 🙂

Building the computer wasn’t so easy as I thought it would be. After putting every component where they belonged the computer booted fine. Then the problems started. My old Windows XP installation cd didn’t contain any sata-drivers as they were supplied in Service Pack 2. I had created the sata-driver floppy but the installation halted on STOP-error “PAGEFAULT_IN_NONPAGED_AREA” or something like that and a reboot later it told that the installation structures were damaged and it refused to continue. I restarted the installation several times just to get various different STOP-errors until I gave up and tried to install Ubuntu.

The Ubuntu installation didn’t start very well as I saw some error messages from the linux kernel, at this point suspicion rised. I rebooted and selected the memtesting from the boot menu of the Ubuntu dvd. What I was encountered with was various memory errors and a lot of red colored characters. OK, my memory chips weren’t working properly. Maybe one of the two Corsairs was broken? I tested them individually and neither of them failed testing. As I put them both back on the motherboard, the failing began again. I wasn’t thrilled at all. Apparently the motherboard fails to recognize the memkit and give them proper settings. Some googling with my laptop revealed that others have had the same problem. I had to manually set some timing and voltage settings in the BIOS. Tadaa! It didn’t fail anymore.

I think it was this site I got the working settings from:

Bios Settings:
SLI-Ready Memory = Disabled
Memory Voltage = 2.085
tCL = 4
tRCD = 4
tRP = 4
tRAS = 12
CMD = 2
Advanced Memory Timings

tRC = 22
tWTR = 15
All other settings = auto

Now I have Windows XP Professional, Windows 2003 Server and Ubuntu Linux installed (I got the Server from MS’ DreamSpark-service for students). Everything seems to working alright

As for performance… well.. none of few games has any performance issues. It was an interesting experience to play Portal and Half-Life 2: Episode Two without any stuttering or glitches. My SimCity Societies is still waiting to be tested as for some reason it keeps telling me about conflicts with emulation software even though I don’t have any emulation software. It seems like someone is going to get cracked.

(The HL2:EP2 achievement about squishing 333 grubs was only 3 bugs away… >:-()