Emulator for computer system input-output adapters

Claim 1

An apparatus for emulating an input-output adapter, for connection to a interruptable computer processor, and computer processor input-output channel, in combination with a plurality of special function input-output adapters, each of which are activated by said computer processor issuing predetermined selection commands over said input-output channel, characterized in that it comprises: a) a command decoder coupled to said computer processor input-output channel, including means for identifying at least one of said predetermined selection commands of at least a first special function input-output adapter, and for generating a first signal upon identifying said first special function input-output adapter selection command; b) an interrupt control circuit connected to receive said first signal, having means for interrupting said computer processor upon receipt thereof, and having means for generating a further interrupt signal, and having means for generating an enable signal; c) an enable circuit coupled to said first special function intput-output adapter, and connected to said interrupt control circuit to receive said enable signal, said enable circuit having means for blocking said first special function input-output adapter selection command unless said enable signal is received; d) an auxiliary processor coupled to said computer processor and connected to receive said interrupt control circuit further interrupt; and e) means is said computer processor for receiving said interrupt control circuit computer processor interrupt, and for determining whether said first special function input-output adapter is to be selected or whether an input-output adapter is to be emulated, and means for transmitting a further command to said command decoder to either unblock said first special function input-output adapter or to generate said further interrupt signal to said auxiliary processor, to cause said auxiliary processor to emulate an input-output adapter.

Claim 2

An apparatus for emulating an input-output adapter, for connection to a interruptable computer processor, and computer processor input-output channel, in combination with a plurality of special function input-output adapters, each of which are activated by said computer processor issuing predetermined selection commands over said input-output channel, characterized in that it comprises: a) a command decoder coupled to said computer processor input-output channel, including means for identifying at least one of said predetermined selection commands of at least a first special function input-output adapter, and for generating a first signal upon identifying said first special function input-output adapter selection command; b) an interrupt control circuit connected to receive said first signal, having means for interrupting said computer processor upon receipt thereof, and having means for generating a further interrupt signal, and having means for generating an enable signal; c) an enable circuit coupled to said first special function intput-output adapter, and connected to said interrupt control circuit to receive said enable signal, said enable circuit having means for blocking said first special function input-output adapter selection command unless said enable signal is received; d) an auxiliary processor coupled to said computer processor and connected to receive said interrupt control circuit further interrupt; and e) means is said computer processor for receiving said interrupt control circuit computer processor interrupt, and for determining whether said first special function input-output adapter is to be selected or whether an input-output adapter is to be emulated, and means for transmitting a further command to said command decoder to either unblock said first special function input-output adapter or to generate said further interrupt signal to said auxiliary processor, to cause said auxiliary processor to emulate an input-output adapter.