IGot24 - a javascript game for calculate 24, hosted on AppEngine

I wrote a small game in the last few days. The game is called IGot24.
The idea is to use 4 basic arithmetic operations to get result 24 from 4 randomly drawn cards. I talked about the algorithm and python implementation in an old post. In fact, it's currently the first result on Google for "calculate 24".

The game is at:
http://calculate24.appspot.com/

I first wrote the game using pure JavaScript. Later I thought whoever play it may want to get solutions. So I created the backend with Google AppEngine that supply cards and solutions. Then I added a few more options, like getting only solvable cards, disabling timer, calculate 42 instead of 24, etc.

The heart of the JavaScript code is a finite state machine. At first I just coded away thinking it'll be simple, then gradually realized there're more states. I then drew a state diagram and found out there were 21 states! They are all branches, there's no loopback, so I don't think they can be optimized. (Maybe they can, but I don't want to re-read my circuit design book from ages ago to find out)

I think the game can be easily re-done in flash using Flex, since JavaScript can be ported to AS3. It can be ported to IPhone too but it will be waste of time and money (to buy a mac to do iphone dev) because I found a "calculating 24" iphone app got downloaded a whopping 12 times.

Chrome OS on Xen HVM

Google announced open-source Chromium OS 2 days ago. today I tried to build it on a Ubuntu virtual machine. But I failed, had numerous problems I won't elaborate. I will try again sometime later.

I searched web and found a VMWare virtual disk of ChromeOS here. So I downloaded it.

Not wanting to install VMWare, I converted it to a raw disk image and loaded it to XEN with HVM, it worked. But it basically unusable for me mainly because of mouse movement was too slow. I will try with a different vnc client later to see if it improves.

Here's how to convert vmdk image to raw:
$qemu-img convert -f vmdk chrome-os-0.4.22.8-gdgt.vmdk -O raw chrome-os.img

Then just specify the image file in 'disk' line of domain config file, like:
disk = [ 'file:/root/chrome-os.img,hda,w' ]

Here's screenshot of chrome OS:


Here's chrome OS login screen, I have a Fedora 12 hvm domain and a Ubuntu 9.04 32bit domainU also running on this machine. The domain0 itself is Fedora 12 64bit with pvops kernel 2.6.31.6.

I had to use standard VGA driver(stdvga=1), the default Cirrus Logic driver give me a screen like this after I login: