Bitboards and a 10x8 board

[Matthias Gemuh]

I thought I could simply modify a few things in my engine to have it play
Capablanca 10x8 chess but it seems impossible because my engine heavily relys
on bitboards.
My compiler knows an 80-bit data type (long double) but can I use bit
operations like & ^ | << >> on this data type ? The MSB (Bit 79) is a
troublesome sign bit, right ?

Matthias.

[Tord Romstad]

I thought I could simply modify a few things in my engine to have it play
Capablanca 10x8 chess but it seems impossible because my engine heavily relys
on bitboards.

Hello Matthias,

It is certainly possible to use bitboards with a 10x8 board, although it will be somewhat more complicated (and of course not quite as efficient). Reijer Grimbergen has a paper about using bitboards in shogi. The shogi board is 9x9, and the problems you face when using bitboards there are mostly the same as you would face on a 10x8 board.

Tord

[Matthias Gemuh]

Hi Tord,
thanks for the paper. I may eventually use unions.

Matthias.

[Reinhard Scharnagl]

As far as I know, Ed Trice is using a bitboard based approach for his 10x8 GothicChess playing Vortex program. He will use it at the Gothic Chess Computer Challenge end of this year. Whether someone else will use a bitboard enhanced engine is unclear to me. My old SMIRF will participate using its own mailbox related approach. Do you also intend to compete there?

Reinhard.

[bob]

Let me also remind you that Slate used bitboards on a machine with a native 60 bit word (CDC). It is about like using bitboards on 32 bit machines, which I did when I first started the Crafty project. Not as efficient, but it can work.

[Matthias Gemuh]

Hi Reinhard,
till I implement a reasonable bitboard class, I may not even create a 10x8 engine.
Best,
Matthias.

[Matthias Gemuh]

A bitboad class is not hard to code. I'll probably do that.

Thanks,

Matthias.

[Dann Corbit]

This thing has already done that (bitboards of all different sizes):
http://www.chessv.com/

[Matthias Gemuh]

Thanks, Dann (nt)