Abstract: A magnetic door stop/latch contains a first magnet mounted on or within a door and a second magnet mounted on or within a structure opposing the door such as a wall, door jamb, door frame or baseboard. When the door is moving towards the opposing structure, the magnetic door stop may used to prevent the door from slamming into the opposing structure by virtue of the repulsive forces of the magnets. The magnetic door stop may be switched from repulsive configuration to an attractive configuration that holds the door in position.

Abstract: A secure computing system stores a program, preferably the real time operating system, that is encrypted with a private key. A boot ROM on the same integrated circuit as the data processor and inaccessible from outside includes an initialization program and a public key corresponding to the private key. On initialization the boot ROM decrypts at least a verification portion of the program. This enables verification or non-verification of the security of the program. The boot ROM may store additional public keys for verification of application programs following verification of the real time operating system. Alternatively, these additional public keys may be stored in the nonvolatile memory. On verification of the security of the program, normal operation is enabled. On non-verification, system could be disabled, or that application program could be disabled. The system could notify the system vendor of the security violation using the modem of the secure computing system.

Abstract: The method of secure computing concerns the security of a debugger/emulator tool commonly employed in program development. A private encryption key is used to encrypt at least verification token for the program. A public decryption key corresponding to the private encryption key is stored at the secure computing system. Upon each initialization of the debugger/emulator the secure computer system decrypts the verification token employing public decryption key. This indicates whether the program is secure or nonsecure. If the program is secure, then the debugger/emulator is operated in a process mode permitting access to the program while prohibiting access to at least one security feature. If the program is nonsecure, then the debugger/emulator is operated in a raw mode permitting access to all features of the secure computing system.

Abstract: A secure computing system prevents unauthorized use of compressed video data stored in a first-in-first-out memory buffer in a set top box. A single integrated circuit includes a data processor and a chip identity read only register storing a unique chip identity number fixed during manufacture. The data processor encrypts the compressed video data stream using the chip identity number as an encryption key. This encrypted data is stored in and recalled from a FIFO buffer. The data processor then decrypts the recalled data employing at least a part of the chip identity number as the decryption key. Using technique the compressed video data stream temporarily stored in compressed form in the FIFO buffer can only be employed by the particular data processor having the unique chip identity number.

Abstract: A toy vehicle has a body having left and right side walls and an arcuate wall extending from front to rear located inbetween the left and right side walls. The body is supported by wheels, a portion of each of the wheels extending upwardly through an opening formed wherein the side walls join the arcuate wall. A cylindrical element is positioned on the vehicle over the arcuate wall between the left and the right side walls so as to rest on the portions of the wheels which extend upwardly through the openings in the arcuate wall. As the vehicle is rolled on a surface, rotation of the wheels of the vehicle is transferred to the cylindrical element to rotate the same on the body of the vehicle. The cylindrical element has a plurality of openings shaped so as to receive a like plurality of blocks. The blocks can be placed within the cylindrical element by inserting them through the appropriate openings.