Abstract: A modified filter screen for use in a downhole drilling operation is disclosed. The filter screen is able to be installed at the surface of a well, and is pin-loaded for easy access and maintenance. The modified filter screen may be retained within a section of pipe below the top drive above the rig floor by allowing dowel pins on the section of pipe to engage with latch slots on the filter screen. The modified filter screen may also be retained by engaging a threaded connector on the filter screen with a threaded connector on the interior of the section of pipe or by utilizing pins and/or retaining rings.

Abstract: A modified filter screen for use in a downhole drilling operation is disclosed. The filter screen is able to be installed at the surface of a well, and is pin-loaded for easy access and maintenance. The modified filter screen may be retained within a section of pipe below the top drive above the rig floor by allowing dowel pins on the section of pipe to engage with latch slots on the filter screen. The modified filter screen may also be retained by engaging a threaded connector on the filter screen with a threaded connector on the interior of the section of pipe or by utilizing pins and/or retaining rings.

Abstract: A baud clock (15) for use by a serial communication interface (67) is generated by dividing a base clock of the serial communication interface by one of a plurality of possible composite divisors (DEG). Each composite divisor is indicative of a minimum time interval by which adjacent pulses of the baud clock are to be separated, and further indicates that at least one pair of adjacent pulses within each symbol interval of the baud clock are to be separated by an extended time interval which is longer than the minimum time interval.

Abstract: A system module 20 includes a processor 10, a system bus 15, a local bus 11 coupled to the processor, arbitration circuitry 12 coupled to the local bus and the system bus for providing common hardware protocol for distributed mode and central mode operations, and protocol control circuitry 13 coupled to the arbitration circuitry, the system bus, and the local bus for providing a system bus request to the arbitration circuitry when the system module desires to perform a bus transaction. The local bus 11 may be a processor bus on a system module while the system bus 15 may be an architecture bus standard such as Futurebus+. Also a method of operating arbiter circuitry in distributed mode or central mode where no change in hardware or software is needed when switching system operations between distributed and central modes.