Abstract: Interlocking knives are provided. The interlocking knives include at least a first knife and a second knife. The first knife includes a blade and a handle. At least one slot may be formed through the blade of the first knife. The second knife also includes a blade and a handle. The second knife includes at least one slot. The at least one slot of the second knife interlocks with the at least one slot on the first knife. A swivel plate may be pivotally connected to the first knife. The swivel plate is operable to pivot towards the second knife into a locked position, securing the second knife to the first knife.

Abstract: Interlocking knives are provided. The interlocking knives include at least a first knife and a second knife. The first knife includes a blade and a handle. At least one slot may be formed through the blade of the first knife. The second knife also includes a blade and a handle. The second knife includes at least one slot. The at least one slot of the second knife interlocks with the at least one slot on the first knife. A swivel plate may be pivotally connected to the first knife. The swivel plate is operable to pivot towards the second knife into a locked position, securing the second knife to the first knife.

Abstract: A data storage system having a plurality of disk drive sections, each one of the disk drive sections having a plurality of disk drives. Each one of a plurality of secondary SAS expanders is coupled to a corresponding one of the disk drive sections. Each one of the secondary SAS expanders has: (1) a plurality of first ports each one being connected to a corresponding one of the disk drives in the corresponding one of the plurality of disk drive sections coupled thereto; and (2) a second port. A main SAS expander has: (1) a first port; and (2) N second ports, each one of the N second ports of the main expander being connected to the second port of a corresponding one of the plurality of N secondary expanders. A storage processor is coupled to the second port of the main SAS expander.

Abstract: A method and apparatus for controlling the flow of data through director elements of a disk drive controller are responsive to external clock signals to synchronize the internal clock timing of each director. The external clock signals are available over either a first master bus or a secondary master bus, each of the buses being connected to the director element. Each director element has circuitry which monitors the occurrence of clock pulses over the buses as well as circuitry for switching, upon the occurrence of a failure of clock pulses on the master bus, from the master bus to the secondary bus for the receipt and resynchronization of clock pulses.

Abstract: A computer storage system includes director boards which control transfer of data to and between a host computer, a system cache memory and a disk array. The directors are provided with features which enhance system performance and reliability. A hardware emulation controller permits a high performance processor to be used with existing system circuitry. A control store memory is organized with primary and secondary data areas and primary and secondary parity areas. Data is written to both the primary and secondary areas. A read request accesses data in the primary area and performs a retry in the secondary area in the event of a parity error. A power supply system includes on-board marginable power supplies to facilitate testing and power-up by-pass circuits for protection of sensitive circuitry. A system clock configuration employs primary and secondary clocks to ensure redundancy of synchronized timekeeping.

Abstract: A data storage system wherein a host computer is coupled to a bank of disk drives through a system interface. The interface includes a system memory comprising a pair of system memory sections. Each one of the system memory sections has a plurality of addressable locations for storing data written into such one of the memory sections at the addressable locations. A pair of system busses is provided, each one of the pair of system busses being coupled to a corresponding one of the pair of system memory sections. A plurality of directors is coupled to the system memory through the system bus. The directors are configured to control data transfer between the host computer and the bank of disk drives as such data passes through the system memory.

Abstract: A method and a control device is provided for upgrading computer system hardware, for example, on a printed circuit board, with system revision information. The method includes receiving, a serial data stream having data bits associated with the system revision information through a serial input of the control device, determining the start of the data bits, and storing at least a portion of the data bits associated with the system revision information within a read-only register of the control device.