hi, i found a c64 recently, and after opening it, i found that it contained the sid chip, but nu a 8580, but a 8580R5, this is actualy a stereo version of the chip ( Double SID chips for stereo sound (8580R5)). Can this chip stil be used, or do i need an older version of the c64, with the 8580 or 6581 chip? kriz