摘要:
A cache memory, when receiving an operand read request and the operand address from a central processing unit, responds with a signal indicative of operand available in the cache, before having checked if such operand is effectively in the cache, if in a previous operand request the effective operand presence in the cache had occurred, or starts a memory read operation, before having checked if such operand is effectively not present in the cache, if in a previous operand request, the effective absence of the operand from the cache has occurred. The decision among the two alternatives is determined by a state logic which stores the previously occurred HIT condition (requested operand present in the cache) or MISS condition (requested operand absent from the cache) and the state of which is updated in the course of a current read operation if a predicted HIT is followed by an effective MISS or if a predicted MISS is followed by an effective HIT.
摘要:
Apparatus and method for clogging prevention in computer printers where a tractor pair (2) pushes a multiple copy continuous form (11) towards a printing position along a path which causes a relative offsetting of the module copies, comprising counting means (26) for detecting that the form (11) has been fed forward of a first predetermined amount and control means responsive to such detection for controlling the tractor pair (2),first in order to feed back the form of another predetermined amount, lesser than the first amount, then in order to feed forward again the form of the same other amount, the control means then resetting the counting means.
摘要:
In a data processing multiprocessor system having distributed shared resources where each system processor (7) is provided with at least a local memory (8) to which it get access through a local bus (11), and with an interface unit (10) for connection of the local bus (11) to a system bus (5) and wherein each of the system processors may have access the local memory of another processor through its own local bus, its own interface unit, the system bus and the local bus of the other processor, deadlock is prevented by providing a bypass unit (40) of the interface unit (10) for enabling access from the system bus to the local bus through the bypass unit, a block (9) connected between the local bus and the interface unit (10) for latching system bus access requests received from an agent processor on the local bus, and a block (12) for isolation of the agent processor outputs from local bus, so that each agent processor may post read/write operations in the related latching block(9) for latching bus access requests and thereafter release its own local bus without waiting completion of the operation, whereby the local bus is available to receive access requests received from the system bus through the bypass unit (40), the operation pending in the latching block (9) being completed, if a read operation, by reconnection of the agent processor (7) and the latching block (9) to the local bus.
摘要:
Multiprocessor computing system wherein a plurality of processors are connected each other through a system bus, each processor comprising a processing unit, a local memory and an interface unit, and wherein the processing unit of any processor has access to both its own local memory and the local memory of any other processor (through the interface unit and the system bus) for concurrently writing into all the local memories an information identified by a destination code as a global data to be concurrently written in all local memories.
摘要:
Belt stretcher for serial printer wherein a spring (14) imparts a predetermined pull to a driving belt (2) by applying a predetermined force to a slide (8) on which a belt return idle pulley (10) is mounted, and wherein slide offsets from a working point and in the direction opposite to the one of the force exerted by the spring (14) are minimized by a stop pad (18), preferably resilient and position adjustable, or automatically changeable in position owing to belt elongations occurring during operation.
摘要:
Memory system comprising a plurality of memory modules, wherein the selection of one among the memory modules is performed in preselection as to the memory activation for a memory access operation , on the basis of the previously performed selection of the same module for a preceding memory access operation and wherein, in case the performed preselection is not the appropriate one, the appropriate selection is first performed and then the memory access operation is "retried".
摘要:
Selective grounding device for electronic equipment comprising a printed circuit board fastened to a grounding frame by a fastening screw inserted in an opening of the board comprising a first conductive pad surrounding the opening and located on the board side contacting the frame, a second and a third conductive pads, insulated from each other surronding the opening on the opposite side of the board, the second pad being electrically connected to the first one, the third pad being electrically connected to the DC ground of the equipment, a washer selectively conductive or insulating, overlaying the second and third pad and clamped on said pads by the fastening screw, so that the DC ground is selectively connected or insulated form the frame ground depending on the washer being conductive or insulating, without need to differentiate, to this purpose, the printed circuit board.