Abstract: A pen-based portable personal computer can emulate the functions of a standard two-button mouse. In particular the system can emulate standard movement and clicking of a mouse buttons as well as emulate both left and right mouse buttons of a two-button mouse. In order to be compatible with various application programs, the system can also emulate the double clicking of the mouse button.

Abstract: An accordion-fold laptop computer, comprising, a first housing having a first edge and an opposing second edge, comprising at least one each of a processor, a hard disk drive and a display screen; a second housing, attached to the first housing proximate the first edge, comprising a keyboard; a third housing, pivotally attached to the first housing proximate the opposing second edge.

Abstract: An improved power source system, which utilizes power from an external source and is adapted for use with a portable electronic device, comprising, a carrying case, for the portable electronic device, having one or more structural components; a battery charge controller integrated into one or more of the structural components; an AC power supply module integrated into one or more of the structural components, connected to the battery charge controller and adapted to receive power from said power source; one or more rechargeable batteries integrated into one or more of the structural components and connected to the battery charge controller; and a DC Output regulator integrated into one or more of the structural components and connected to the battery charge controller.

Abstract: A computer system having a power monitoring device places a write-back cache memory into a write-through mode upon detection of a low-battery condition or a user request. Under write-through mode, the cache memory need not be flushed every time a suspend mode of the computer system is entered. Thus significant power is saved during typical portable computer operations.

Abstract: A dedicated network expansion unit includes a processor and a dedicated hard disk drive, and has two bays which each can receive one of a further hard disk drive, a floppy disk drive, a CD-ROM drive, and a tape drive. The unit has no manual input mechanism, and no display for text or graphics. The unit can be connected to one or more communications link through Ethernet connectors, a PCMCIA modem card, a PCMCIA token ring card, or a parallel connector. Following power-up or a reset, the unit automatically detects the types of devices present and the types of communications link connected to it, and automatically configures its software to operate properly with these devices and links, without user interaction. Special software routines are provided for the unit and a remote computer to permit a conventional backup program in the remote computer to effect a backup operation within the expansion unit using ASPI commands.

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. When running a multi-tasking operating system where an application program is being executed in a restricted mode, a suspend/resume operation can be carried out in which the system is substantially powered down and then powered back up, and will resume the interrupted application with the restricted mode back in effect. Further, set-up changes such as adjustment of the processor speed can be made without exiting the application program running in the restricted mode.

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.