Abstract: The present invention is a desktop personal computer (PC) system having peripheral device bus mastering. The system has a Direct Memory Access (DMA) controller for transferring data to and from the memory of the desktop PC system. A hardware state machine is used for programming the DMA controller, generating and sending command signals, and receiving completion status after the transfer of data is complete. A bus controller is used for implementing a memory data transfer request from the DMA controller means and said hardware state machine means. A device controller, either a Universal Serial Bus (USB) controller or an Infrared Data Association (IrDA) controller, is used for receiving and responding to the command signals from the hardware state machine means, transferring data to and from the DMA controller means, and generating and returning a completion status to the hardware state machine means after the transfer of data is complete.

Abstract: The present invention is a desktop personal computer (PC) system having peripheral device bus mastering. The system has four main elements: a Direct Memory Access (DMA) controller, a hardware state machine, a bus controller, and a device controller. The device controller may be an IDE hard disk controller which is able to generate long streams of data in an intermittent fashion wherein any single stream of data is targeted to a number of different host memory locations. The device controller may also be an ECP parallel port controller which interfaces with a number of different peripheral devices over a parallel bus wherein each peripheral device appears to the system as a separate and independent data path.

Abstract: A miter attachment capable of use on radial saws, table saws, drill presses, router tables, and the like, comprises three legs of a triangle. The longest leg constitutes an elongated base member. This base member is pivotally attached at one end to a fence member. The base member has a track in it for engagement by a slider, which is capable of movement along at least a portion of the length of the base member. The slider is pivotally attached to one end of a coupler arm, the other end of which is pivotally attached to the fence member at a point spaced from the end pivotally attached to the base member. As the slider is moved to different relative positions along the length of the base member, the coupler arm causes the angle between the fence and the base member to change.

Abstract: A system for altering a clock frequency to a logic controlling device that controls logic which runs at a fixed frequency slower than a frequency of a computer system running the logic. The system speeds up the clock signal to a logic controller when the logic controller is arbitrating between different operational requests. When the logic controller acknowledges a specific operational request, the clock controller immediately slows the clock signal down in order to allow a command strobe length that the logic device executing a specific operation request requires.

Abstract: A venturi-type system for cooling a roof by rapidly moving the hot air beneath roof tiles. The air cooling system is passive, and accelerates the evacuation of hot air from beneath roof tiles by creating a venturi system at the uppermost portion of an angled tile roof.