CLAUDY , Is the MCP23017 not some sort of I/O expander from MicroChip? You do not need PBP to use it. It is not a processor but an mearly a periferal to allow more I/O pins to be added to an exsisting processor. If the processor you are using is indeed from MicroChip then you can use some of the I2C or Shiftin/Shiftout commands to access it's registers provided if the PBP language.

Dave Purola,
N8NTA