Monday, December 23, 2013

USB Chessboards

Bryan Whitby features a nice USB Chess Board website with a lot of information and links on USB chess boards. On this site, you can find details on hardware and software for connecting a chess board to a tablet or computer. A must read for anyone who enjoys playing computers but prefers playing on a real board.

I, obviously, especially liked the video of Frank Walls Android USB board that features Chess for Android. I have embedded the video below.

Saturday, December 21, 2013

Chess OCR

Gerhard Roth wrote various very interesting chess OCR applications that enable you to scan chess positions from books and open these directly in your favorite chess application for further analysis. Much faster than manually entering these positions through a position setup editor.

The application supports the Android sharing mechanism I blogged about a while back. For example, as illustrated below, first open a chess book at an interesting position, then invoke Gerhard's OCR application to scan the position, and finally select sharing to open, for instance, Chess for Android for further analysis with your favorite UCI or XBoard engine.

Chess for Android version 4.5 also introduced a fast way to invoke Gerhard's application. Long press the notation window, and the select Retrieve Position. This will bring you back in the OCR application again (or give you a choice if several such applications exist) to scan the next position. Great job Gerhard writing this nice Android application!

Monday, December 9, 2013

Chess for Android v4.5

It has been a while since the last update, since I have been a bit busy at work, but I finally had some time for two new features in Chess for Android, version 4.5 now available through the playstore or as direct download:
  • Spoken chess text (option to announce all moves)
  • Retrieve position function (direct link with Gerhard Roth's OCR app)
To enable the new chess speech feature, simply press the menu button, select "Options", and then enable the "Spoken Moves" option (see check-mark below). After that, Chess for Android announces the chess moves made on the board, as well as the final outcome of the game. For now, only the english language is supported.

A follow-up posting will go into more detail on the OCR feature.

Saturday, November 30, 2013

Chess for Android on a Smartwatch

A few days back I got a very kind email from Branko with some pictures of Chess for Android running on a Galaxy Gear smartwatch. I never tested a much smaller screen, and was glad the scalable drawing methods displayed the board rather well. Thanks Branko for these pictures and your nice email!

Wednesday, October 2, 2013

Eyepiece Projection Continued

Because the 26mm eyepiece does not fit in the Meade basic camera adapter, and the 9.7mm eyepiece has too much light loss in my modest Meade ETX-90EC, I purchased a 15mm eyepiece. This eyepiece fits comfortably in the adapter. Less magnification than the 9.7mm eyepiece, of course, but therefore also less light loss.

Below already a quick result (taken at dawn) together with two pictures from the September 7 posting (taken during the day) for comparison. The slight curvature in the picture is a bit worrisome, still have to look more into that. Can't wait though to try some real astrophotography with the new eyepiece.

prime focus (rear port)

9.7mm eyepiece projection (adapter)
15mm eyepiece projection (adapter)

Tuesday, September 10, 2013

Prime focus vs. eyepiece projection

Since the moon is back at a normal hour, I could do some more experiments with astrophotography. Below a comparison between prime focus and 9.7mm eyepiece projection photograph of the moon using an Meade ETX-90EC. Disappointing result for the latter, since a digital zoom on the prime focus photo is much more clear.

Saturday, September 7, 2013


If you are following me on Facebook or Google+, you probably noticed that lately I have been less busy with chess programming. Instead I have been spending  free time at my Meade ETX-90EC telescope getting familiar with astrophotography.

Here are some of my first pictures using prime focus configuration (single shot manual exposure, using mirror lockup and remote control to minimize vibrations).  I really like the clarity of the moon picture and was happy seeing the ring of Saturn so clearly.

I also tried eyepiece projection configuration, but found this extremely challenging. Due to the inherent light loss at higher magnifications, it is very hard to find and focus the object (hints from experienced astrophotographers welcome!).

Today I have been experimenting with the different configurations during daytime. Below you see some sample pictures of my neighbors house number sign, taken with the camera's 300mm telelens for reference and three ETX configurations (note that the camera adapter configurations affect the picture's orientation differently). The last picture was taken at ISO-6400 to get about the same light exposure. Even during daytime, it is hard to get a good picture, which probably means I have a lot to learn. But it is a really interesting hobby!

300mm telelens
prime focus (rear port)

prime focus (adapter)
9.7mm eyepiece projection (adapter)

Sunday, July 14, 2013

Friday, July 5, 2013

Chessbase compatible engines continued

I am about to release a next version of Chess for Android that recognizes engines in the Chessbase compatible format discussed in the previous blog posting. The new version is available as direct download or from Google Play.

With this release, all engines installed in this format (either the engines that ship with the Chessbase for Android application itself, or engines installed in this format, such as my own Engines.apk package) are available for direct import in Chess for Android as well as in the latest Chessbase for Android.

Together with sharing capabilities, this greatly enhances the 'chess ecosystem' on Android, since chess GUIs can now be used interchangeably in a much simpler manner.

As before, engines authors that want to be included in the package can drop me an email.

Thursday, July 4, 2013

Chessbase compatible engines

Chessbase announced UCI engine support in Chessbase for Android too. Great news!

I have packaged some chess engines in Chessbase compatible format so that they are directly available in that application. I will also release a new version of Chess for Android that supports this format to keep the chess ecosystem complete.

Simply download and install the Engines.apk (no need to run the app). The package is also available from Google Play.

For now, the package only contains BikJump versions, but any chess author that wants to be included is welcome to drop me an email with permission to include the binary in that APK.

Tuesday, June 4, 2013

Android Tournament: Group A

Today, the last five seconds-per-move tournament in Group A completed, played from both sides of all positions in the Silversuite gambit opening suite. The Komodo DEV engine crashed in a few fixed positions, and the games had to be adjudicated, unfortunately. Games available at the tournament site.

This concludes my 2013 Android engines tournament.

Congratulations to Richard Vida for Critter's victory, his second Android tournament victory!
1 Critter 1.6a     *         27.5-22.5 38.0-12.0 38.0-12.0 48.0- 2.0 151.5/200
2 Stockfish 2.3.1  22.5-27.5 *         42.0-8.0  37.5-12.5 45.5- 4.5 147.5/200
3 Toga II 3.0      12.0-38.0  8.0-42.0 *         43.0- 7.0 39.0-11.0 102.0/200
4 Komodo DEV       12.0-38.0 12.5-37.5  7.0-43.0 *         31.0-19.0  62.5/200
5 MinkoChess arm    2.0-48.0  4.5-45.5 11.0-39.0 19.0-31.0            36.5/200

Saturday, June 1, 2013

Android Tournament: Group B

Group B in the ongoing 2013 chess tournament between UCI and XBoard engines for Android just completed a five seconds-per-move tournament played from both sides of all positions in the Silversuite gambit opening suite. Congratulations, again, to Toga II, which was updated from version 1.4.1SE to version 3.0, for its promotion to Group A.

Games available at the tournament site.

                   1         2         3         4         5
1 Toga II 3.0      *         26.5-23.5 33.5-16.5 46.0- 4.0 45.5- 4.5 151.5/200 => TO A
2 Gaviota v0.86    23.5-26.5 *         33.0-17.0 36.5-13.5 44.0- 6.0 137.0/200
3 DiscoCheck 4.0.1 16.5-33.5 17.0-33.0 *         32.5-17.5 41.5- 8.5 107.5/200
4 Rodent 0.18.0     4.0-46.0 13.5-36.5 17.5-32.5 *         31.5-18.5  66.5/200
5 Pepito v1.59      4.5-45.5  6.0-44.0  8.5-41.5 18.5-31.5 *          37.5/200

Saturday, April 27, 2013

TI-89 calculator example

Here is one of the first examples I tried, taken from the 1981 high school sample exams. Consider the function f given by x -> x^2 / (x |x| + 1).

On the TI-89, it is best to enter functions in the Y= window for easy reference later. The calculator also features pretty printing of the function after entering the raw definition, as shown below using the y1 slot.

Now, the graph feature plots the function, nicely accounting for the asymptotes.

One of the questions was to solve f(x) < 1/2 x. On the TI-89, this can be done with the solve function on the just entered y1 function. The solution is given on one line, so a bit of scrolling is required, but it is correct.

Another question was to compute the area under the function on the interval [0,1]. This is easily done with the integral function, as shown below.

Pretty neat, right?

TI-89 graphic calculator

I treated myself with this Texas Instruments TI-89 Titanium calculator. I really like the computer algebra system and graphic capabilities. Although a bit retro compared with what one can do on a regular desktop, I was impressed to see this calculator solve all my high school advanced calculus questions symbolically by just pressing a few buttons.

Saturday, April 13, 2013

Android Tournament: Group C

Group C in the ongoing 2013 chess tournament between UCI and XBoard engines for Android just completed a five seconds-per-move tournament played from both sides of all positions in the Silversuite gambit opening suite. Congratulations to Toga II for its promotion to Group B.

Games available at the tournament site.
1 Toga II 1.4.1SE *         30.0-20.0 33.5-16.5 36.0-14.0 37.5-12.5 137.0/200 => B
2 Arasan 15.2 JA  20.0-30.0 *         27.0-23.0 27.5-22.5 35.0-15.0 109.5/200
3 Texel 1.01      16.5-33.5 23.0-27.0 *         29.5-20.5 35.0-15.0 104.0/200
4 crafty-235      14.0-36.0 22.5-27.5 20.5-29.5 *         30.0-20.0  87.0/200
5 Rotor 0.8       12.5-37.5 15.0-35.0 15.0-35.0 20.0-30.0 *          62.5/200

Saturday, March 30, 2013

Android Tournament: Group D

Group D in the ongoing 2013 chess tournament between UCI and XBoard engines for Android just completed a five seconds-per-move tournament played from both sides of all positions in the Silversuite gambit opening suite. Congratulations to Crafty its promotion to Group C.

Games available at the tournament site.
1 crafty-235      *         31.0-19.0 34.5-15.5 31.5-18.5 37.5-12.5 134.5/200 => C
2 cheng3 1.07 JA  19.0-31.0 *         25.0-25.0 30.5-19.5 33.0-17.0 107.5/200
3 Daydreamer 1.75 15.5-34.5 25.0-25.0 *         26.5-23.5 30.0-20.0  97.0/200
4 scorpio-27-ja   18.5-31.5 19.5-30.5 23.5-26.5 *         29.0-21.0  90.5/200
5 GarboChess 3    12.5-37.5 17.0-33.0 20.0-30.0 21.0-29.0 *          70.5/200

Thursday, March 14, 2013

Android Tournament: Group E

Group E in my 2013 chess tournament between UCI and XBoard engines for Android just completed a five seconds-per-move tournament played from both sides of all positions in the Silversuite gambit opening suite. Congratulations to Garbochess 3 for its promotion to Group D.

Games available at the tournament site.

1 GarboChess     *         26.5-23.5 32.5-17.5 32.5-17.5 33.5-16.5 125.0/200 => D
2 sloppy-023-ja  23.5-26.5 *         25.0-25.0 31.0-19.0 23.0-27.0 102.5/200
3 danasah-488-ja 17.5-32.5 25.0-25.0 *         23.0-27.0 29.5-20.5  95.0/200
4 tucano104-ab   17.5-32.5 19.0-31.0 27.0-23.0 *         25.5-24.5  89.0/200
5 betsabe-II-130 16.5-33.5 27.0-23.0 20.5-29.5 24.5-25.5 *          88.5/200

Wednesday, March 6, 2013

Android Tournament: Group F

The test and qualification rounds of my 2013 chess tournament between UCI and XBoard engines for Android are over and the group tournaments have started.

Group F just completed a five seconds-per-move tournament in Group F played from both sides of all positions in the Silversuite gambit opening suite. Congratulations to betsabe-II-130-android-ja for its promotion to Group E.

Games available at the tournament site.

1 betsabe-II-130     *         26.0-24.0 31.0-19.0 36.0-14.0 37.5-12.5 130.5/200 => E
2 phalanx-xxii-ja    24.0-26.0 *         21.5-28.5 33.5-16.5 37.0-13.0 116.0/200
3 typhoon-android-ja 19.0-31.0 28.5-21.5 *         28.0-22.0 35.0-15.0 110.5/200
4 TJchess 1.01U      14.0-36.0 16.5-33.5 22.0-28.0 *         27.0-23.0  79.5/200
5 kmtchess-121-ja    12.5-37.5 13.0-37.0 15.0-35.0 23.0-27.0 *          63.5/200

Tuesday, February 12, 2013

Test Runs for the 2013 Tournament

I have completed the initial tests for the 2013 tournament between engines for Android (compiled for ARMv5TE) using Chess for Android on a Nexus 7 (1.3 GHz quad-core Cortex-A9). The qualified and disqualified engines are shown below.  Next to follow is a qualification tournament which will place the top 25 engines in six groups, like I did in the 2011 tournament.

However, I will wait a few days to see whether engine authors want to appeal the disqualification with an improved binary. Updates of qualified engines are of course also welcome.


AdroitChess 0.3     
Arasan 14.0.1
BikJump v2.1P (32-bit)
cheng3 1.07 JA
Critter 1.6a 32-bit
Daydreamer 1.75 JA
Diablo 0.5.1      
DiscoCheck 4.0.1  
GarboChess 3 (32-bit)
Gaviota v0.86    
GNU Chess 6.0.2
Jazz 6.40 JA
Pepito v1.59  
RedQueen 1.1.2 
Rodent 0.18.0
Rotor 0.7       
Simplex 0.9.8 
Stockfish 2.3.1   
Sungorus 1.4 JA
TJchess 1.01U
Toga II 1.4.1SE


amundsen (illegal moves)
apilchess-106-ja (hangs)
bruja (hangs)
buzz-os-11-27-08-ja (crashes)
cassandre-026-ja (sends wrong format)
chess-one-201-ja (crashes)
cyrano-061-b17-ja (hangs)
dirty-android (old compilation)
gfc-08-rev5-ja (claims win without mating move)
gullydeckel-215-pl10-ja (uses too much time)
ifrit-m18-ja (illegal moves)
iota (uses too much time)
knightcap-36-ja (crashes)
komodo3 (old compilation)
mizar-30-ja (uses too much time)
mskcp-145-ja (uses too much time)
pawny-031-ja (illegal moves)
rocinante-101-ja (hangs)
sissa-20-ja (illegal moves)
suff-03a-ja (uses too much time)

surprise-43-b13-ja (uses too much time)
umko_1.2_arm (hangs)
zeta-dva-0202-ja (illegal moves)

Saturday, February 9, 2013

2013 Android Engine Tournament

My 2013 tournament between UCI and XBoard engines for Android (ARMv5TE-based) using Chess for Android is about to start with the test and qualifying rounds. I have setup a tournament website with past tournaments (one old, one new so far). The new tournament results will be posted in this blog and at the 2013 tournament site. Games will be played on a Nexus 7 (1.3 GHz quad-core Cortex-A9). If supported, engines will be allowed to use multi-threading.

Let the games begin! If you don't see your favourite engine in the test tournaments, feel free to drop me a request.

Friday, January 11, 2013

Chess for Androidv 4.1.5

I just released version 4.1.5 of Chess for Android as direct download and at Google Play with enhancements for, what I like to call, the chess ecosystem on Android. First, as explained in my prior blog posting, Chess for Android now understands a few more direct sharing requests from other applications so that, for example, a game can be shared directly from Gerhard Kalab's Chess PGN viewer into Chess for Android, without going through tedious copy-and-paste operations. Conversely, Chess for Android now supports the "Share Game" feature as well to do the opposite operation.

As illustrated below (long-press notation window to open the extended menu), exporting a game from Chess for Android to the Chess PGN Viewer now only takes a few simple clicks!

Tuesday, January 8, 2013

More on application/x-chess-pgn

In January 2012, I posted a blog entry on registering Chess for Android as viewer for the application/x-chess-pgn MIME type. Under this approach, when an Android application requests viewing a game in PGN format, Chess for Android will open that game. If several programs register as viewer, the user can select what program should be used.

Recently, I got an email from Gerhard Kalab, author of Scid on the Go and Chess PGN Viewer, with a request to support the application/x-chess-pgn MIME type for data sent through an Intent.EXTRA_TEXT as well. After adding this feature, Gerhard's viewer can now share a game with Chess for Android, as shown below. For example, to share a game from the Chess PGN Viewer, press menu, select "Share", and then "Share game". This lists possible target programs, including Chess for Android. Picking the latter opens Chess for Android with the currently viewed game.

Nice to see the Android chess ecosystem develop more and more!