Thanks a lot Archangel!

It is not the installation problem indeed: picbasic has changed since I have used it for the last time. In the newest version we have to use the following type of config for 16f88!

#CONFIG

__CONFIG _CONFIG1, _CP_OFF & _CCP1_RB0 & _DEBUG_OFF & _WRT_PROTECT_OFF & _CPD_OFF & _LVP_OFF & _BODEN_OFF & _MCLR_ON & _PWRTE_ON & _WDT_OFF & _INTRC_IO
__CONFIG _CONFIG2, _IESO_OFF & _FCMEN_OFF

#ENDCONFIG