Abstract: A personal digital assistant module with a local CPU, memory, and I/O interface has a host interface comprising a bus connected to the local CPU and a connector at a surface of the personal digital assistant for interfacing to a bus connector of a host general-purpose computer, providing direct bus communication between the personal digital assistant and the host general-purpose computer. In an embodiment, the personal digital assistant also stores a security code. The personal digital assistant according to the invention forms a host/satellite combination with a host computer having a docking bay, wherein upon docking a docking protocol controls access by the host to memory of the personal digital assistant based on one or more passwords provided by a user to the host. In another embodiment the personal digital assistant also has an expansion port connected to the local CPU, and expansion peripheral devices may be connected and operated through the expansion port.

Abstract: A compressed I/O bus system for a general-purpose computer multiplexes 32 bit data and addresses on 32 of 42 dedicated parallel signal paths, and optimizes the bus structure by mapping bus requests made by peripheral devices to "high" memory portions of system RAM not dedicated to other purposes. In one aspect a bus controller is programmable to select translation routines stored in system RAM, allowing various models and types of CPUs to be supported. In this aspect, supported CPUs are interchangeable in the system. In another aspect a default interface attaches to the compressed I/O bus of the invention, and translates bus states between the optimized compressed bus and one of an ISA bus or an EISA bus.

Abstract: A personal digital assistant module with a local CPU, memory, and I/O interface has a host interface comprising a bus connected to the local CPU and a connector at a surface of the personal digital assistant for interfacing to a bus connector of a host general-purpose computer, providing direct bus communication between the personal digital assistant and the host general-purpose computer. In an embodiment, the personal digital assistant also has a means for storing a security code.The personal digital assistant according to the invention forms a host/satellite combination with a host computer having a docking bay, wherein upon docking a docking protocol controls access by the host to memory of the personal digital assistant based on one or more passwords provided by a user to the host. In another embodiment the personal digital assistant also has an expansion port connected to the local CPU, and expansion peripheral devices may be connected and operated through the expansion port.

Abstract: A personal digital assistant module with a local CPU, memory, and I/O interface has a host interface comprising a bus connected to the local CPU and a connector at a surface of the personal digital assistant for interfacing to a bus connector of a host general-purpose computer, providing direct bus communication between the personal digital assistant and the host general-purpose computer. In an embodiment, the personal digital assistant also stores a security code. The personal digital assistant according to the invention forms a host/satellite combination with a host computer having a docking bay, wherein upon docking, a docking protocol controls access by the host to memory of the personal digital assistant based on one or more passwords provided by a user to the host. In another embodiment the personal digital assistant also has an expansion port connected to the local CPU, and expansion peripheral devices may be connected and operated through the expansion port.

Abstract: A bus interface system for expanding the I/O capability of a portable computer utilizes a parallel port connector with master interface circuitry connected to the internal ISA I/O bus of the portable computer and driving a 25-conductor Centronics-type cable as an intermediate bus. The master interface circuitry is device-driver-transparent, and multiplexes address, data, and control information over a byte-wide avenue of the intermediate bus according to premapped state translation tables. In a preferred embodiment a single peripheral I/O device comprising a slave circuitry may be connected to the 25-pin port, and the slave circuitry demultiplexes the intermediate bus states, providing a synthesized sub-set of ISA states to drive the peripheral device. In another embodiment a docking box comprises a bus with multiple I/O ports, such as a network port, a COM serial port, and additional floppy and hard disk drives.

Abstract: A dual mode raster scanned character display system has a text mode of operation in which characters having a first matrix size are displayed on a CRT screen and a high resolution mode of operation in which display information is bit mapped on the CRT screen. Programmable font characters are stored in a memory and are accessed by controller characters generated in response to display requests supplied by an associated information source, such as a computer or a keyboard. Each controller character includes a special screen attribute multi-bit portion which is used to modify the font characters when coupled to a video signal generator unit to display reverse video, provide underline or strike through, specify one of two fixed intensities, suppress the character or provide a software function, such as CURSOR. In text mode, each character block has a fixed size appropriate to alphanumeric character generation, i.e.