Abstract: The invention relates to a bus controller for a bus (7) which can be used by several masters, characterized in that it comprises at least two modules (7a, 7b) each of which contains an arbiter and an arbiter supervisor, the function of one at least of the arbiter supervisors being to enable the output of the arbiter of the same module as long as it observes that this arbiter is operating correctly and to disable this output when it observes that the arbiter of the same module is not operating correctly.

Abstract: The invention relates to a computer farm, comprising a bus (7) on which is simulated a local area network between several processor cards (3a-3h) mounted on the bus. Each card comprises a test function (11) which implements, upon execution thereof, at least part of the functionalities required for simulating the local area network on the card and a module for executing the test function, whilst the farm comprises a test means which periodically executes the same calculation as the same test function and compares its result with the result provided by the card.

Abstract: The invention relates to a computer farm, comprising a bus and processor cards (3) mounted on the bus, each card comprising a luminous indicator (7) provided so as to switch on and switch off when the card is powered up and when it is shut down, wherein said farm comprises a means for switching on and switching off the same luminous indicator (3) upon the input and/or output of data in the card

Abstract: The invention relates to a computer farm comprising a bus (7) and several processor cards (3a-3h) mounted on the bus, each processor card executing an operating system able to manage external system modules by way of drivers.

Abstract: The invention relates to a computer farm, comprising a bus (7) and several processor cards (3a-3h) mounted on the bus, an address of a memory area, so-called state area (8), being predefined for each location of the bus which may receive a processor card.