Abstract: A digital computer system has a central processor unit (CPU). A computer program, entered into the digital computer system for execution thereof, has a program code word embedded at an arbitrary location therein. An addressable programmable array of logic (PAL) is operatively connected to the CPU for receiving a READ signal originated by the CPU at the address of the PAL, the PAL being programmed to output a portion of a preset array code word in a response to the READ signal, and to output the remainder of the array code word in segments in response to subsequent READ signals at the same address. A data bus, connected to receive and transmit the portion and remainders of the array code word to the CPU for comparison with the program code word. The program code word and the array code word are compared and, if identical permit use of the program and do not permit use when the program code word and the array code word are not identical.

Abstract: A battery-powered lap-top computer has a main battery for ordinarily supplying power to the computer circuitry. A reserve battery is connected through an automatic switch to the circuitry. The circuitry is connected to a pair of contacts and the switch is connected to a contact. The main battery has positive and negative terminals, and a removal terminal which is shorter in length than the positive and negative terminals. When the main battery loses its charge, it is removed by a sliding action which slides the terminals past the contacts, the removal terminal being the first terminal to lose contact. This activates the automatic switch, connecting the reserve battery into the circuitry so that when the positive and negative terminals are no longer contacted, the reserve battery will have been supplying and will continue to supply power to the circuitry. A charged main battery is then installed, deactivating the switch, removing the reserve battery from the circuitry.

Abstract: A hinge assembly has a plurality of rollers which are pressed against an elastic washer by a shaft. The rollers and elastic washer are contained within a cylindrical retainer which is held in a fixed position relative to a first bracket, while the shaft is held in a fixed position relative to a second bracket so that, when either or both the first and second brackets are moved relative to each other, the roller move around the outside diameter of the shaft resisted by the elastic washer, providing a smooth resistance to the movement of the first bracket and/or second bracket relative to the other. An electronic digital device, having a display section with an adjustable viewing angle utilizing the improved hinge assembly, is shown in which the hinge assembly provides a smooth resistance for the movement of the display section relative to the base of the device.

Abstract: An electronic digital computer has a warning facility for indicating activity and operation, or lack of same, of the central processor in the system. It is done by providing a signal indicative of continuing operation of the central processor to activate an indicator circuit. The indicated circuit utilizes an RC circuit for maintaining a high level through a high comparator when the processor is operational. When the central processor becomes non-operational, the capacitor discharges to a point where a low comparator responds, causing the capacitor to begin charging to its high value. The associated circuits, using this feature, maintain an LED in the active stage until such time as there is no signal indicating continuing operation of the central processor, at which time the LED begins an approximate 50% duty cycle resulting in a blinking indicator.

Abstract: An integrated circuit is formed in a semiconductor chip and connected to at least a first source of voltage and at least a second source of voltage, negative with respect to the first source of voltage. A number of integrated circuit components are activated by the first and second sources of voltage and are interconnected to provide desired functions. An integrated circuit capacitive element in the form of the gate capacitance of a field effect transistor and in the form of a reversed biased diode is connected between the first and second sources of voltage to decouple integrated circuit inherent inductance in series with the first and second sources of voltage.

Abstract: A personal computer has a chassis having a plurality of expansion slots in which are mounted optional Input/Output (I/O) expansion cards. At least one first expansion card has a first bracket adapted for connection to a mounting fixture. At least one second expansion card has a second bracket that is not adapted for connection to the mounting fixture. An adapter bracket is provided which is configured to connect to the mounting fixture and also to the second bracket to provide mounting of the second expansion card in one of the expansion card positions.