DDR1, DDR2, SDRAM? How to determine a PC's memory when upgrading

I have a desktop i bought in 2004. It's still working fine but I wanted to upgrade its 256 MB memory. But how do I know which type of RAM to buy? Without a manual, I took a look at the label of the existing RAM - it says there 256MB DDR 266MHz. But what is the maximum amount of memory I can insert?

I found this very useful application which can tell me what my RAM types are and more:

System Information for Windows by Gabriel Topala

www.gtopala.com

Note that each RAM slot has a maximum memory capacity and the motherboard has a total maximum capacity. It doesn't pay to insert 3 1 GB DDR's in a motherboard with a maximum 2GB capacity.

Upgrading Without a Recovery Disk

My Lenovo 3000 C100 did not come with any Windows XP CD. Instead, the OS is embedded in the harddrive. I do not like this arrangement. First, it takes up precious space in the harddrive. Second, should the harddrive get useless, how do I upgrade?

And so with only 40GB (32 GB only with 8GB reserved by XP for Rapid Restore) my laptop quickly lost space. I bought an 80GB disk (the website says my laptop model can only accomodate up to 100GB and there was no such size in the market) and agonized whether I should install Mandriva or Ubuntu instead.

The decision to remain in XP was arrived at when I realized I would not be able to program in Matlab since my Matlab license is for Windows. Oh well, I can always dual boot. Scilab is fine but would need more improvements in image processing.

Fortunately, I found that it is possible to make a Windows Installer from such embedded OS. The original link seems no longer active. But here's a tip : In google, type How to Fresh Install Windows XP Without a Recovery CD. I thank profusely the one who figured this out.

What to do when your cellphone refuses to send and receive text messages

After a year and a half of using my Sony Ericsson P990i it suddenly lost the ability to send and receive text messages. Turning it off and on again resulted in an "MsvServer" error. Canceling this message sometimes lead to intermittent bursts of queued SMS's. I also receive a message saying the SIM card is already full even if I've erased much of its contents.

What worked was the suggestion of my friends who experienced the same problem.

The solution - MASTER RESET. Just make sure you've backed up all your contacts and other important data from your phone.

Master Reset is found in the Control Panel->Device menu.

Inserting images as background for OpenOffice Calc graphs

(Thanks to Eduardo David Jr. for tip.)

In verbatim, Ed's advice:

"1.)Click the plot ONCE
2.)Choose Area (see attached image)

3.)Go to Bitmaps tab, then choose Import
4.)Select the image
5.)Double click the plot then choose Chart Area
6.)Under the Area tab, choose Bitmap
The imported image should appear in the list :D"

General Comments on the handwritten text activity (morphological operations) AP 186

I was delighted to find several of you succeeding in getting the outlines of the handwriting right. I noticed several common mistakes though:

1. Morphological operations work on white blobs. Most of you had the background on white and the handwriting in black. Such image must be bit-inverted (0 becomes 1, 1 becomes 0). So even if you did opening and closing with the intent of fixing the handwriting, the operations opened and closed the background.

2. The choice of structuring element is critical. Most of you simply used a 2x2 struct element even if this was not appropriate. Some of you wisely chose a 4x1 element since most handwriting have vertical elements. I would suggest that if the handwriting is slanted, use a slanted structuring element as well.

Finally, a tip. If the processed handwriting is fat, you might want to use thin to make it one pixel thick.

Image Histograms in Scilab

Two solutions were found by my students to display the histogram of a grayscale (or indexed) image.

The first solution is a code written by Jeric
//Jeric Tugaff
//Histogram
im=imread('grayscale.jpg'); //opens a 24 bit image
im=im(:,:,1);imwrite(im(:,:), 'gs.jpg'); //converts to 8 bit grayscale
imageim=imread('gs.jpg');
val=[];
num=[];
counter=1;
for i=0:1:255
[x,y]=find(im==i); //finds where im==i
val(counter)=i; num(counter)=length(x); //find how many pixels of im have value of i
counter=counter+1;end
plot(val, num); //plot. :)

The second was found by Jorge, a built-in function

histplot([0:1:255],c);

where c is the image variable.

Collective comments on Activity 1 AP 186

AP 186 08-09 Class:

Most of you got the technique right. 10 point for those with correct reconstruction. 11 points for those with convincing overlays. There are a few who forgot the following important details, though:
1. The journal source - a number of you didn't cite what journal and paper they got the graphs from.
2. Collaborators - some of you forgot to mention who helped you. Please tell if you did it independently. Part of the learning is learning from each other. If you're not certain, ask around. If you're certain, share.
3. Details on how you got your graphs - some of you had no explanations.
4. Self-evaluation - remember you give your grade. If i think you got lower or higher than what you deserve I'll change it.