Information processing system with an operation console for processing both normal operation and maintenance commands

An information processing system provided with an operation console for processing both normal operation processing commands and maintenance processing commands comprising:

• a function key included in said operation console for selectively generating first and second output signals;
• first and second information processing units connected to said operation console, each of said information processing units including a main memory, a system controller connected to said main memory, a CPU connected to said main memory through said system controller, and a fault diagnostic unit;
• first and second interfaces for connecting said fault diagnostic unit of said first and second information processing units, respectively, to said operation console;
• a microprocessor in said operation console having a first operation mode for executing at least said normal operation processing commands and a second operation mode for executing both said maintenance processing commands and said normal operation processing commands, said microprocessor further having at least one microinstruction memory for storing an interruption processing routine and a maintenance command processing routine for controlling the execution of said maintenance processing commands, and means for selecting said first operation mode in response to said first output signal and said second operation mode in response to said second output signal;
• a flexible disk connected to said microprocessor for storing an abnormality processing routine;
• means for transferring an interruption signal to said microprocessor of said operation console through said first and second interfaces upon the detection of a fault in at least one of said first and second information processing units by at least one of said fault diagnostic units included in said first and second information processing units, said interruption signal being transferred from said first information processing unit through said interruption signal transferring means to said microprocessor operating in said first operation mode, said microprocessor for first accessing and executing said interruption processing routine stored in said microinstruction memory and then for accessing and executing said abnormality processing routine read out of said flexible disk through said microinstruction memory;
• means for switching said microprocessor from said first operation mode to said second operation mode after the execution of said abnormality processing routine is terminated;
• and
• means in said operation console for selecting said first information processing unit for the execution of said maintenance processing command and said second information processing unit for the execution of said normal operation processing commands.