A maintenance interface is provided for interfacing a service processor and a central processing unit operating asynchronously to each other. The maintenance interface includes circuitry for synchronizing the service processor to the central processing unit and decode circuitry for interpreting commands...http://www.google.fr/patents/US4268902?utm_source=gb-gplus-shareBrevet US4268902 - Maintenance interface for a service processor-central processing unit computer system
Maintenance interface for a service processor-central processing unit ...