Last month i rewrote my bool solver from scratch. This time i wrote it in pure C - without C++ elements. It has almost all functions of the old version plus some new ones, but the new program is much shorter. Documentation and comments are in german... thats why i do not upload it.
Because the old firmware (version 4) of the AtTiny clock was pretty ugly, i rewrote and changed many parts of the firmware. The new version has the number 5. The new code runs like a charm and as a bonus it eliminates the problems i had with the buttons (it was not a hardware problem).
Release will be soon. Only a calibration function for the quartz is still missing. ^.^°
And one last thing: i disassembled my old Acer travelmate 220 notbook and under the sticker of an IC i found an Atmel AtTiny25 as part of the charging circuit. It communicates directly with the laptop battery through TWI/I²C. The foto was made with my Canon EO350 / Digital Rebel XT / Kiss Digital N with an hand hold lens in retro position - the IC was so damn small: