A computer system is made capable of accepting more than one type of central processor including a plurality of sockets for receiving more than one type of identification signal, a clock generator responsive to said identifying signal for generating clock signals for the identified type of processor,...http://www.google.com/patents/US5546563?utm_source=gb-gplus-sharePatent US5546563 - Single chip replacement upgradeable computer motherboard with enablement of inserted upgrade CPU chip
