Abstract: An adjustable keyboard assembly for a portable personal computer includes a keyboard, split along a predetermined breakline defining two keyboard sections, removable from the portable personal computer. In order to facilitate angular positioning of the keyboard sections as well as removal of the keyboard sections from the portable personal computer housing, the keyboard sections are mechanically coupled together, for example, with a hinge at one end of the breakline. Such a configuration enables the relative angular positions of the keyboard sections to be custom positioned by the individual user for maximum adjustability in accordance with the user's preference both on and removed from the portable personal computer housing. Unlike other known keyboards, the keyboard, in accordance with the present invention, is formed in standard QWERTY format so as not to require retraining of users.

Abstract: An enhanced parallel port interface increases the bandwidth of a standard parallel port connector while at the same time maintaining backward compatibility with a standard parallel port interface. In order to increase the data transfer rate, the software overhead is substantially reduced by hardware generated signals. As such, the desirability of using a parallel port bus expansion is greatly increased.

Abstract: A computer system as provided with an internal flash ROM which includes the BIOS. In the event the flash ROM becomes corrupt, a special purpose interface allows for mode switching of a standard parallel port from a standard peripheral interface, such as a printer interface to a special purpose interface to enable the BIOS to be executed from an external ROM or another computer connected to the parallel port.

Abstract: A power supply system, for example, for use with a portable personal computer, includes a smart battery pack and a charging system. The smart battery pack is provided with a dedicated microcontroller for controlling the charging level of the battery charger system. In particular, the status of the battery including the voltage and temperature of the battery is applied to the microcontroller along with a signal representative of the current load demand of the computer system. The micro controller, in turn, provides a control signal in the form of fixed frequency, variable duty cycle pulse width modulated (PWM) signal for controlling the charging level of the battery charger system. The duty cycle of the PWM signal is used to regulate the charging current supplied by the battery charger. In particular, the DC value of the PWM signal is used as a reference to control the charging current of the regulator to provide a variable output charging current with a relatively wide current range.

Abstract: An apparatus and method for tracking and interception of instructions as they are presented to the memory, selectively passing harmless data to the device and disallowing the sequences which instruct the device to perform harmful functions, such as self-erase. A software trap is provided to be transparent to the operation of the device and the host system, imposing no harmful timing delays or software overhead. Accordingly, the invention allows the use of standard electrically erasable read-only memories in an application which requires that the device be protected from global erasure. A hardware front end intercepts the software command which is used to globally erase the device.

Abstract: An adjustable keyboard assembly for a portable personal computer includes a keyboard, split along a predetermined breakline defining two keyboard sections, removable from the portable personal computer. In order to facilitate angular positioning of the keyboard sections as well as removal of the keyboard sections from the portable personal computer housing, the keyboard sections are mechanically coupled together, for example, with a hinge at one end of the breakline. Such a configuration enables the relative angular positions of the keyboard sections to be custom positioned by the individual user for maximum adjustability in accordance with the user's preference both on and removed from the portable personal computer housing. Unlike other known keyboards, the keyboard, in accordance with the present invention, is formed in standard QWERTY format so as not to require retraining of users.

Abstract: A control circuit which allows computer systems to modify signal timing relationships in the hardware via programmable ports in the system, thereby allowing timing adjustments to be made without effecting motherboard hardware. The control circuit includes a plurality of delay devices configured to provide a plurality of delays under program control. The control circuit is adapted to extend the duration of a write signal to enable data to be latched, normally on the trailing edge of the write signal to avoid latching invalid data.

Abstract: A port replicator is disclosed that provides for the efficient connecting and disconnecting of peripheral devices to a computer. A replicator port connector is provided on a portable computer that duplicates the pins of a other peripheral connectors on the computers. The housing of the port replicator is attached by spring clips to the computer which covers the other peripheral connectors replicated by the port replicator. The replicated connectors are then reproduced on the connector housing. Cables for peripheral devices can remain connected to the connector housing but be connected to and disconnected from the computer in a single action.

Abstract: A drive platform assembly for a personal computer for carrying both floppy disc drives and hard disc drives which facilitates the installation and replacement of such disc drives. The drive platform assembly includes a drive platform and an expansion platform. The drive platform is adapted to carry a 3.5 inch floppy disc drive and two 3.5 inch (1-inch height or a single 1.56-inch height) IDE hard disc drives. A mounting bracket is provided for carrying either a floppy disc drive or a hard disc drive that is rotated into place within the drive platform. Once rotated into place, the mounting bracket is automatically grounded. The mounting bracket is adapted to be secured to the drive platform relatively quickly and easily without the use of fasteners. An expansion platform is provided and adapted to be releasably secured to the drive platform to form the drive platform assembly. The expansion platform is adapted to carry additional floppy or hard disk drives.

Abstract: A power supply system, for example, for use with a portable personal computer, includes a smart battery pack and a charging system. The smart battery pack is provided with a dedicated microcontroller for controlling the charging level of the battery charger system. In particular, the status of the battery including the voltage and temperature of the battery is applied to the microcontroller along with a signal representative of the current load demand of the computer system. The micro controller, in turn, provides a control signal in the form of fixed frequency, variable duty cycle pulse width modulated (PWM) signal for controlling the charging level of the battery charger system. The duty cycle of the PWM signal is used to regulate the charging current supplied by the battery charger. In particular, the DC value of the PWM signal is used as a reference to control the charging current of the regulator to provide a variable output charging current with a relatively wide current range.

Abstract: A computer system has a memory and has a processor coupled to the memory, the processor having an access control arrangement for delaying completion of a memory access until the occurrence of a control signal. A deterministic circuit coupled to the-processor and the memory has a register arrangement containing control information loaded by the processor, the deterministic circuit having a signal generation arrangement for generating the control signal. The signal generating arrangement includes a selective delay arrangement which can selectively delay generation of the control signal during an access to the memory by a time interval having a duration which is a function of the control information in the register arrangement.

Abstract: A laptop computer system includes a protected mode microprocessor capable of operating in restricted and unrestricted modes, and an arrangement which in response to a predetermined condition saves information from the processor and then forcibly switches the processor to its unrestricted mode of operation. The system includes a first interrupt mask register having a bit for indicating whether an interrupt is to be recognized by the processor, a second interrupt mask register having a bit for indicating whether the interrupt is to be recognized by a further circuit, and an arrangement responsive to a load of the first mask register for conforming the bit of the second mask register to the bit of the first mask register in a manner invisible to an application program being executed by the processor.

Abstract: A power supply system, for example, for use with a portable personal computer, includes a smart battery pack and a charging system. The smart battery pack is provided with a dedicated microcontroller for controlling the charging level of the battery charger system. In particular, the status of the battery including the voltage and temperature of the battery is applied to the microcontroller along with a signal representative of the current load demand of the computer system. The microcontroller, in turn, provides a control signal in the form of fixed frequency, variable duty cycle pulse width modulated (PWM) signal for controlling the charging level of the battery charger system. The duty cycle of the PWM signal is used to regulate the charging current supplied by the battery charger. In particular, the DC value of the PWM signal is used as a reference to control the charging current of the regulator to provide a variable output charging current with a relatively wide current range.

Abstract: A symmetric multiprocessing system with a unified environment and distributed system functions provides unified address space for all functional units in the system while distributing the execution of various system functions over the functional units of the system whereby each functional unit assumes responsibility for its own aspects of these operations. In addition, the system provides improved system bus operation for transfer of data from memory.

Abstract: A symmetric multiprocessing system with a unified environment and distributed system functions provides unified address space for all functional units in the system while distributing the execution of various system functions over the functional units of the system whereby each functional unit assumes responsibility for its own aspects of these operations. In addition, the system provides improved system bus operation for transfer of data from memory.

Abstract: A relatively fast system control processor, such as an Intel 8051, is substituted for an Intel 8042 microprocessor in a PC/AT type compatible personal computer. In one embodiment of the invention, a System Control Processor Interface (SCPI) is provided between the central processing unit (CPU) and the system control processor (SCP) to maintain compatibility with the PC/AT bus. The combination of the faster SCP and the SCPI interface improves the overall system performance. Control circuitry is also provided for setting the A20 signal relatively quickly to allow memory access above one megabyte. In an alternate embodiment of the invention, a Mouse Keyboard Interface (MKI) is provided. The MKI provides even quicker switching of the Gate A20 signal by eliminating the need to interrupt the SCP. The MKI also provides support for a type PS/2 mouse.