I forgot to mension that R was zero (not mounted) and that capasity on
input base is high and does that it is more independent to length of
wire on rows. Increase of R may cause problems because of lower
amplification. I think that it is better to use a capacitor on each row
to be sure that no keys realy conduct.

I am very interrested knowing if it exist a version for a PIC.

Regards,
Jens Dyekjfr Madsen