Compaq Computer Corporation, Inc.

Christopher E Simonich

Robin T Tran

Kevin B Leigh

David R Wooten

Craig A Miller

Robert Brett Costley

Michael R Durham

Lee B Hinkle

A computer system which includes an electromagnetic hoodlock, and does not have any simple way to bypass the hood-lock The hoodlock consists of a spring-loaded solenoid, and is controlled by the system microprocessor. The system chassis may only be opened by a user with sufficient rights, after entering a password, or after an administrative command is sent over the computer network.

Electronic hood lock

A security methodology and security logic for protecting Plug and Play computer system components from unauthorized access. The security logic prevents modification of the base addresses of specified Plug and Play computer system components by blocking writes to specific index locations programmed into security registers. In the disclosed embodiment of the invention, the base address of a Super I/O chip is protected, as well as the base addresses of specified logical devices in the Super I/O chip. Protecting the base addresses in this manner prevents the security logic from being circumvented by interfering with the address decoding used to track reads and writes to protected index registers. In addition, the security registers are programmed to prevent access to the protected index registers of the logical devices.

Security methodology for devices having plug and play capabilities

In a personal computer system utilizing both a main power supply and an auxiliary power supply, the input and output signal lines of auxiliary powered components are selectively isolated from components powered solely by the main power supply. Gating circuitry and buffer circuitry, controlled by various enable signals, are used to isolate the signal lines. External pull-down or pull-up resistors are no longer required, which frees up printed circuit board area for other components and conserves board space in the computer system.

Personal computer component signal line isolation for an auxiliary powered component

A PCI-based computer system is provided with an expanded number of PCI master devices, in effect a second level of PCI arbitration. The expansion is made available without requiring additional bridge chips. Multiple PCI devices may arbitrate for control of the PCI bus via the primary PCI bus controller without requiring a specifically assigned signal pair, yet appear to system software to reside on the primary PCI bus.

Computer system for supporting increased PCI master devices without the requiring additional bridge chips

A run-time security methodology and apparatus for supporting complete access to the security features of a network computer by a network administrator. In a network computer according to the invention, various resources are secured by a security device. The resources are accessible by a computer user with knowledge of one or more user passwords stored in the security device. An administrator password is also stored in the security device. In addition to control access to specified resources, the administrator password also functions as a surrogate for the other passwords stored in the security device. An administrator password implemented according to the invention thereby allows a network administrator to remotely override any activated user security settings and receive complete access to a secured network computer.

Method and apparatus for providing remote access to security features on

A security device and methodology that prevents unauthorized access to general purpose I/O pins in a computer system. In a system according to the invention, secure general purpose I/O pins are utilized as enable signals for data transfer devices such as Universal Serial Port (USB) ports. In one embodiment of the invention, access to the secure general purpose I/O pins is governed by an administrator password that is protected by a memory slot in a security device. When an administrator (or other authorized user) desires access to the general purpose I/O register that controls the secure general purpose I/O pins, the administrator enters the administrator password. If the password is correct, the relevant slot of the security device is unlocked, thereby permitting completion of write cycles to the secure general purpose I/O register. If a write cycle to the secure general purpose I/O register is attempted while the relevant slot in the security device is locked, the write cycle is ignored. Control and monitoring of various system resources in a secure manner is thereby permitted via use of the secure general purpose I/O pins.

Secure general purpose input/output pins for protecting computer system

When a computer system's power button is depressed a timer is begun, an operating system visible status flag is set, and an interrupt is sent to the operating system indicating power button activation. If the operating system does not clear the flag within a specified time period, the computer system is considered to be in an error (e.g., 'hung' state) and the computer system is powered down.

Power management of a computer system using a power button

A point to point connection architecture for a computer I/O subsystem, resulting in a scalable tree structure. A Master I/O Concentrator (MIOC) is connected to the host bus and handles conversion between a bus oriented structure and the tree structure of the I/O subsystem. Ports away from the host bus are downstream ports and conform to a simple byte wide message protocol. Various IOCs and devices can be attached to one of the downstream ports on the MIOC. The MIOC directs transmissions to the appropriate channel based on a geographical addressing scheme. The IOC connections act as further points of branching. Ultimately IOD or I/O devices are reached, having an upstream port for connection to the IOC and a downstream port and internal logic appropriate for the particular peripheral device. Various registers are present in the IOCs and the IODs to allow determination of the topology and particular devices present. Messages and commands are transferred in the I/O subsystem in defined packets. Various read, write and exchange commands are used, with a read response being utilized to allow split transaction read operations. Certain status and control commands are also present. Interrupts are handled by having the interrupt levels correspond to memory addresses of the programmable interrupt controller, thus allowing simple selection of interrupts to be generated by the devices and no need for separate wiring.

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Hillsboro, OR, United States of America

Christopher E Simonich