Fighting with computers

I've heard some news about troubles with VirtualBox when running on Snow Leopard. It was too late for me as I've just upgraded a couple of my systems. So I installed VirtualBox and I created a sample Ubuntu 9.04 system from scratch. Everything ran smoothly. Network and USB access worked as expected too. I have no idea if there is trouble running a VM you created before upgrading to Snow as I have none. I used to be a fan of VMware's free VMplayer. Unfortunately there seems there is not a free version OS X. VirtualBox appears to do a nice job too. There is a quirk though, USB devices need to be registered to be used by the VM before you turn it on.

While reviewing some of the answers to one of the questions of Code Jam Round 1C, I've learned about this cool software . It can be run using Java Web Start , so you don't even need to install it. What is it about? I reckon it will make some Math teachers very very happy. In short, it is a drawing tool for geometry-oriented drawings. It can export to SVG or EPS too. Mastering on the use of the program may take a while, but I see lots of potential on this tool.

I've failed to make it to round 2 of Code Jam 2009 last weekend. I failed on getting the first problem (All your bases) right and that ate most of my available time. I was able to get the third one (Bribe the prisoners) right (bruteforcing it, not very elegant). So I used some time to get the first problem right after the contest :-) By the way, I later learned that there was a hidden constraint, as output value could not be larger than 10^18. That meant that maximum base could be 16 (as 1023456789abcdefg is base-17 is larger than that, 49030176097150555672 in case you're wondering). Here you have a simple solution in Java . And, yes, you can use Long.toString(String,int) instead of BigInteger, though the latter will cover a wider range than the problem statement requirements.

A few days ago I've got a shiny new MacBook Pro. Instead of coming with Snow Leopard installed, I've got a rebate on the price for the cost of the update to SL. I've installed Snow Leopard now but the disc does not contain a version of X11. As GIMP and Inkscape software depend on that I'm searching for the r ight version to install . I could use some help if you already know where to pull it from. Update : I'm happily running the GIMP on Snow Leopard. Contrary to my claim above, X11 is included on Snow Leopard, you'll find it in the Applications part of the optional install package.

Yep, it does sound odd, so a bit of an explanation may be welcome: I've bought me an electronic book reader a while ago (a Papyre 6.1 from Grammata). It is the same device as the Hanlin v3, Bebook, LBook and many other brand names given by sellers on different countries. The reading experience has been quite good. Actually it's been better than I expected. However, every now and then, like Windows 98, the system would refuse to turn page and freeze. After a few seconds [I suspect] the built-in watchdog timer quicks in and reboots the system. Total time is less than 30 seconds but the worst part is that you've lost the book page you were in. After checking several forums where many users complain about the same thing but no real solution was offered, I learned that an "alternative" firmware was available for a wide range of devices, including mine. Even better, there was a live version you could try before flashing it on your device. Who could ask for more? This...

I've just passed the qualification round of Code Jam with the feeling that I'm getting dumber every year. I only passed the first problem (Alien) and I've got stuck on the second problem (Water Basins). Third one (Welcome string) looked like the Speed Limit problem on 2008, but I did not attempt to do it. A plausible excuse is that I did not have the time ... Yes, I like that: I was busy working so I did not have time to waste playing this Code Jam thing. BTW, It was me the guy who asked about the error message on the Q&A. The error message said my solution file did not start with the string "Case #1:" but that was not true. The correct error message should have been that my solution file did not start with the string "Case #1: ". The difference being the space after the colon. Update: Here you have the three problems solved in Java.

A the moment of writing this, Gmail is giving the usual Server Error message you get when things go wrong. I hope the problem will be fixed soon. I've learned that Twiter can be useful whenever this happens. You can check by yourself with this query . There is also a reporting tool from Google that can come in handy.

As a Gmail user I've sometimes trouble with certain email alias unhappy of me sending from an SMTP server outside of our campus network. Another source of weirdness is the fact that while the From: field shows what I want, there is also a, sometimes not hidden, "On behalf of" that is broadcasting my gmail account even when I'm not interested on doing so. It's great that Gmail has added a new feature that allows Gmail servers to use your organization SMTP server as the outgoing SMTP server for your corporate email address. The two above mentioned problems are fixed then: You can send to email alias only intended for local users just right from Gmail (no nasty Outlook anymore, thanks). And secondly, there is only now the right From: mailbox. Cool!

From time to time we witness significant changes on how things are done. In terms of how we listen to music in the last ten years I've seen several interesting changes. Ten years ago I bought my wife her first MP3 player: It was Diamond Multimedia with 32 MB (yes, Megabytes) that could hold a couple CDs of 128kbps MP3 music. Since then on I've bought many other MP3 devices for my household. However, that marked the end of traditional media (CD-audio) for our portable uses. While MP3 players have been around for quite a while, it seems that Apple's iPod is now the king. And while kingdoms do not last long in this market I guess Apple has done something right. Many people (like myself) are device-centric. For quite a while I favored Creative players and while I've never bought music from iTunes, I've bought some software there. Meanwhile I've stopped buying from Creative after problems with several players. And now that I have time I've played a bit with anot...

It's been hectic times around here, mostly due to different changes at my workplace. Now it's time to start thinking on having some vacation. A summer trip seems a good idea but this year I've selected Norway : beautiful but expensive. While there are tons of information on-line, I have found details are a bit sketchy. This is likely due to the fact I'm interested on cheap accommodation. Maybe the average wages in Norway are much higher than in my home country, Spain. I've got some trouble getting things done online. There seems to be some odd behavior and this booking website , when browsed with Firefox on Ubuntu 8.04. The worst thing is that it was this the browser I was using when booking my flight with Norwegian.com and I was offered a very competitive car-rental price at the end of the airplane booking process. Unfortunately when trying to go to book the car I was offered an almost empty page. I was wrong when I thought I could go back to the former page too. S...

No, I'm not going to complain about the output quality (at least not yet as I'm still waiting for my order). What I want to complain about is the fact that your iPhoto Book orders do not show up on your Apple Store account. And apparently this oddity has been happening for quite a while . That means that there is no way for you to know about your order status. Of course there is a confirmation email sent to your Apple ID email but, what if your .mac account has expired? (then you no longer have access to that email). To make things worse, once 1-click order has been activated iPhoto will not ask you for an additional confirmation when issuing a new order (I guess that's the 1-click beauty once your Apple ID email account works nicely). Calling customer service did not help much, as I was assured my credit card was not billed and somehow I had no pending orders. Calling my bank gave me another version: My credit card was billed (and apparently my order was taking longer tha...

Not yet very affordable, but better than I expected. This is my opinion after buying an ebook reader. Mine is branded Papyre 6.1 but it's named Hanlin v3 in other countries. It's manufactured in China (what a surprise!) and it runs Linux (it has an ARM processor). Definitely worth watching at. However I have not used it for more than a few minutes so I do not have an opinion about the long term usefulness of the device. But if it delivers what I've seen in the tests it is more than worth it. Now I'm sorry but I'm back to reading, please do not disturb. Update: The reading experience has been better than expected. And the availability of contents has also been better than expected. What I have not find, however, is a shop with the latest books. But that only meant some books cannot be bought but they might be available somewhere ... For example, I was reading a paper copy of this book in Spanish. And I had no trouble finding an electronic version. There is a cheap...

Years ago, in a distant galaxy, I was a member of ICSI . Now I've been surprised about one their offerings to the community: A network analyzer . It's Java-based so it won't work unless you have Java support in your browser and you're happy running digitally signed code. You may learn a couple of things about your network connection.

A succession of breathtaking sequences shot from the air is the newest release by this widely awarded photographer. It's really worth watching. You can get the movie for free! Movie is available in theaters all over the world (but apparently not in USA) and also in YouTube in HD . Although the beauty of the images might be better enjoyed on the big screen, you can have a look at it on-line. What amazes me is that it is the creators of the movie who decided to release it on YouTube at the same time than in theaters. The release details were given on a press conference . The movie has been sponsored by PPR , a French multinational in the fashion business.

I've found the network transfers to take forever on this device. Between 1 and 2 Mbytes/second is really slow by todays standards. It means around 4GB per hour. I'm happy with the torrent download functionality I mentioned on a previous entry but there is a catch: What if your download contains a sequence of RAR files? Yep, it happened to me with a 16GB download. Moving this back and forth to a PC would took more than 8 hours!! So the obvious idea is ... why not to have unrar command on the SPP? And this is what I did. I looked for the source code , and using a buildroot ext2 image file I compiled unrar command . Now I can telnet to my box and launch it without the need of moving files back and forth. It's not lightspeed but it's minutes instead of hours. The other improvement was to add SSH functionality by borrowing dropbear binary from OpenWRT project . Please have a look at dropbear documentation so you can install in properly on your system (a few files and links ...

My old analog camera is also giving me trouble. The symptom was that many pictures had just a small fraction of the total field. This can happen when shooting with flash if the sync speed is not correct (flash fires when shutter is half-open only). However this time I was shooting outdoors without a flash. After a few iterations with Google led my to a photo on Wikipedia with exactly the same type of residue I've found on my camera. A few more searches led me this article that explains the causes of the problem and a possible fix. Aging and heat turn a piece of foam inside the camera guts into an oily tar that ruins the shutter operation. Did you think you can keep on using your old camera, maybe not if it as a twenty years old Canon EOS.

One of the bad things about DSLR (aka Digital Reflex) cameras is the tendency to get dust in the image sensor (as these cameras use removable lenses). Whether it is just dust or pollen it may eventually be shown in your photos (like the spot I show on the right: it is just blue sky). For not so big spots, they may go easily undetected. If you want to check for dust in the sensor the simplest way seems to take a photo of the blue sky with the smallest aperture possible on your lens (F22 in my case). Detecting the problem only serves to make you nervous, but fear not, it can be fixed. There are different ideas and people who would talk for or against any of them. I do not feel comfortable risking my camera sensor without reading quite a lot before doing one thing or another. Apparently there are several ideas that can help: Air blower. Dry dust removers. Wet dust removers. Send the camera to the manufacturer for a professional cleaning of the sensor. The first three is something you can ...

Programming when your target system is not based on x86 architecture and you use a PC for development can be done using a cross-compiler. There is a GNU cross-compiler for many different platforms. What if you'd like to test the code without using the target system. There are good news too, as you can use qemu emulator to get a system with a non-x86 architecture emulated on your x86 system. But you might want to get a development system running on your same target hardware. This is interesting if you have a way of accessing the target computer filesystem. It can also be interesting if you want to be able to fine tune the set of versions and libraries to be used by your development system. Here is when buildroot comes in handy. Buildroot allows you to create a development environment for your embedded system around uClibc (which is a scaled-down version of glibc used for many Linux-based embedded systems). With this tool you select the architecture, kernel, compilers and librar...

Some people are keen on the idea of using cellphones as a remote control. After all they are usually around, have a small size, a nice display and even some of them have an illuminated keyboard. Among the choices for interfacing with another equipment, Bluetooth seems to best choice: more standard than infrared and lower power requirements than wifi (besides not many phones have IR or wifi). Around this concept of using your Bluetooth cellphone as a remote was created AnyRemote project. I've tried lately for a home project and I'm very happy with this suite. Yes, it is actually a more complex system than I expected: You cellphone needs a special program to act as a remote, this program in written in Java and you need to download it to your phone. Then server software is installed in your computer and a set of configuration scripts tell your computer what to do when each key is pressed. On the other hand, user menu is provided on cellphone display (there is even a midnight com...

Hardly more than 90 days old, our MacBook 2.4 was already featured here as it has already caused me some trouble. Not a good thing I have to talk about it again: Yesterday it stated to make fan noise when idle, and the display backlight was changing for no apparent reason. After several unsuccessful attempts, I've found this article about resetting SMC as somewhere else I was suggested it might help. Unfortunately though the SMC reset did help with the fan noise it left my system with no ambient light sensor. Whether it was related or not I do not know, but now I cannot use F5/F6 to change the keyboard backlit which remains off. I get a forbidden sign as if the ambient light was very high so as not to require any keyboard backlit. Unfortunately this seems not to be the case in my dark room and it still refuses to allow me to switch the backlit on. The next exercise on the list was to perform a PRAM reset, that did not fix anything either. And, according to Apple support, the next ...