Posts

Chess for Androidv 4.1.5

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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!  

More on application/x-chess-pgn

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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!

Chess for Android v4.1

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I just released version 4.1 of Chess for Android, available at Google Play or as direct download (including a version with network/SMS permissions). The new features include: Ability to send SMS messages (PGN, FEN, UNICODE, engine analysis) Ability to enable/disable built-in book (useful when imported engine book should be preferred) Larger engine analysis font Further localization and internationalization To send an SMS, long-press the notation window, and select "Send SMS", which pops up the window shown below. Simply fill out the phone number (which will be remembered for next time), and select between PGN, FEN, or UNICODE format (or engine analysis of an imported engine). Pressing the "Send SMS"  button will send the text message. The concise FEN format will be useful for correspondence players, since it can be directly copied and pasted by the other player (I have not implemented an SMS listener yet). The UNICODE format sends the current chess

Commodore 64 still runs!

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Like many others, I learned Basic and 6510 machine code on the Commodore 64, a present from my dear grandfather and parents. Although nowadays one can relive the good old times with emulators, such as CCS64 or Vice, and a cross-assembler, like my own win2c64 , nothing beats the real deal! Today I tried to get my old Commodore 64 and 1541 disk drive, bought in Europa, running again. A few 110-220V adapters, a S-Video cable, and some PAL/NTSC settings later, I have my old friend running again. What made me extra happy is that the 1541 could still read the 5¼" floppy disks with my old programs that I wrote back in the eighties, such as the music editor on the screen shot. I am going to try to copy those onto my hard disk, so others can run these in an emulator.

BikDam: international checkers

Inspired by Rein Halbersma's kind encouragement, I have started some work on an international checkers engine. After all, " dammen " is the variant I grew up with in The Netherlands. Since I have implemented BikJump for chess, BikMove for American checkers, I decided to name this upcoming engine BikDam . I already had some fun hacking a, hopefully, efficient move generator. The rules for captures were very interesting to implement. Here are the perft number from the start position of 10x10 international checkers (a.k.a. dammen). In contrast with my American checkers move generator, here duplicate captures are removed. perft(1) = 9 in 0 ms. perft(2) = 81 in 0 ms. perft(3) = 658 in 0 ms. perft(4) = 4265 in 0 ms. perft(5) = 27117 in 1 ms. 27117.0 KN/s perft(6) = 167140 in 3 ms. 55713.3 KN/s perft(7) = 1049442 in 22 ms. 47701.9 KN/s perft(8) = 6483961 in 78 ms. 83127.7 KN/s perft(9) = 41022423 in 434 ms. 94521.7 KN/s perft(10) = 258895763 in 2599 ms. 99613.6 KN/s perf