Computer system including a device with a plurality of identifiers

A computer system wherein first and second computers and a peripheral device are connected through a common bus, and wherein the first and second computers access the peripheral device;

• comprising:
• means for allocating peculiar device ID's to the first computer and the second computer, respectively;
• and
• means for allocating a plurality of device ID's to said peripheral device;
• a specified one of said plurality of device ID's of said peripheral device being used for only the access by said first computer;
• another of said plurality of device ID's of said peripheral device being used for only the access by said second computer.

A computer system having first and second computers, and a peripheral device which is connected to only the second computer;

• comprising:
• means for allocating peculiar device ID's to the first computer and said peripheral device, respectively;
• and
• means for allocating to said second computer a device ID which is peculiar to said second computer, along with the same device ID as the device ID allocated to said peripheral device;
• said first computer including means for issuing a command to said second computer by designating the allocated device ID of said peripheral device in order to access said peripheral device;
• said second computer including means for accessing said peripheral device upon receiving said command, and for sending a result of the access to said first computer.

A computer system having a plurality of computers which include first and second computers of different communication protocols, and a peripheral device for the plurality of computers;

• comprising:
• means for allocating peculiar device ID's to said first and second computers, respectively;
• and
• means for dividing a function of said peripheral device into a plurality of sub functions corresponding to a plurality of communication protocols, and for allocating peculiar device ID's to the respective ones of said plurality of sub functions;
• said first and second computers accessing said peripheral device by the use of said device ID's corresponding to said communication protocols of their own, respectively.

An external storage device which is accessed from a computer by designating a device ID of the external storage device;

• comprising:
• division means for dividing said external storage device itself into a plurality of partitions;
• memory means for storing peculiar device ID's for the respective partitions obtained with said divisions means;
• comparison means for comparing said device ID designated by said computer, with the plurality of device ID's stored in said memory means;
• and
• control means for accessing the partition which corresponds to the device ID having coincided as a result of the comparisons by said comparison means, and for sending a result of the access back to said computer.