Mobi - a FICS and ICC chess client for portable devices

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The Mobi chess client for handheld mobile devices intended for use on the Free Internet Chess Server and the Internet Chess Club should be possible to run on any device that supports something called Java MIDP 2.0 and can run Java programs as large as 100 KBytes. Most of the mobile phones except the most basic ones sold today do, and some older ones that support only Java MIDP 1.0 are rumored to support the necessary functionality to run Mobi too.

Mobi has now been tested on a number of different devices and is known to be working on:

  • Nokia series 40 phones
  • Sony Ericsson phones
  • Samsung phones
  • Motorola phones
  • Phones with the Windows Mobile operating system, supporting pointer device (tested on Qteks)
  • Symbian based devices which many so called smartphones are, mainly those from Nokia (series 60 and series 80) and Sony Ericsson
  • Palm computers running Palm OS, supporting pointer device (but screen updates seem to be very slow on the Java implementation on Palm OS and reports range from slow but usable to practically unusable; probably depending on the processor speed)

It is now known why the standard version of Mobi does not work on the Nokia 9500. The Java impementation in this device is faulty and a workaround exists (the help text is not available in this version). Contact me ( if you want to run Mobi on a Nokia 9500. In one case a Samsung phone has not been able to connect to a server, giving a security violation message; maybe it was incorrectly configured, I don't know. A Blackberry phone has also failed to connect, the reason is still unknown. I have also encountered a problem with a Sony Ericsson V600i (on which Mobi works fine when connected to a 3G network) when connected over GPRS with an old SIM card that didn't support 3G. There was often a huge lag when receiving data over this SIM card. There is a workaround, but as long as nobody runs into this problem (you should use a modern, 3G enabled, SIM card with this phone) I will igore it.

Mobi will adapt to the language that the device is set to use (the language your menus are displayed in, usually set in some phone settings menu). The currently supported languages are English and Swedish. Mobi will default to English for languages that are not supported.

How to get Mobi to your phone:

To use Mobi you should find out how the chess server you are planning to connect to (the Free Internet Chess Server or the Internet Chess Club) works by studying its website and connect to it using an ordinary computer. When you understand the basics, it shouldn't be more difficult to use Mobi.

To get it to your phone, connect to the Internet with your phone and go to either if you phone browser supports HTML or to if you have only a WAP browser in your phone and download it from there. If you want to download it to your computer first you can go here with your computer browser and get the files Mobi.jad and Mobi.jar and install Mobi from your computer if you have the equipment to do that.

It should be possible to run Mobi by studying the information that is accessible through its help menu, which can also be found here. It supports the most commonly used commands through menus but you can give any command by entering it as text and you can bring up a console window to see what really goes on.

I see that Mobi can now be found in the download section at the FICS web site, and if you are a registered user you can go there and give Mobi a rating or post a comment.

And a word of advice:

Find out what it is going to cost you to connect to the Internet with your phone. Make sure (by contacting your operator) that you can make a data connection with your phone and that it is configured to do so, otherwise it will connect with an ordinary phone call and you will be charged for an ordinary call for the whole session. Also make sure you know what the data traffic will cost you. Transfering a move for one player takes about 160 byte, so a game of 40 moves will be about 13 KB. Use the command 'Traffic Meter' to see the exact status for your session. I don't know much about rates in other countries, but with the Swedish operators it doesn't cost very much to play chess over the phone.

Another note:

As entering moves can not be as fast as it can on an ordinary computer with a graphical user interface and a pointer device (unless you are one of those lucky who own a device which has a pointer device) and as timeseal/timestamp (protocols that compensate for slow data transfer) are not implemented, cell phone chess playing is not so well suited for the faster time controls. On a third generation cellular network I seem to lose about 0.2-0.4 seconds per two half moves (one move for each player) due to the transfer times, but using GPRS I seem to loose about four seconds with every two half moves. Implementing timeseal/timestamp, if I could be allowed to do that, would make a big difference when response times are long.


Finally, some pictures of phones running Mobi and screenshots of a couple of different emulators with different screen sizes and in different languages:

Photo of Mobi on a Nokia N93 Photo of Mobi on a Nokia 6234

Screenshot of Mobi Screenshot of Mobi Screenshot of Mobi

Screenshot of Mobi Screenshot of Mobi Screenshot of Mobi

Screenshot of Mobi