but can't follow you.
The link to the "base version" just shows 2 directories which are model dependant. Can't find any base version but
Also the news page says :
This update allows to run pbchess on the PocketBook 602/603/902/903. Tested with PocketBook 602; "
Unfortunately there is no pbchess-188.8.131.523_60x_90x file on any page.