Abstract: An apparatus for storing and monitoring a plurality of articles, including at least one cabinet or carrier having a plurality of receptacles in which the articles are stored. In one application, the apparatus is utilized to maintain a library of magnetic tapes or other storage media associated with a data processing center. Each of the articles is identified by a respective code or volser number, and requests for the articles are received by the system in the form of requests for a particular volser number. In a preferred embodiment, the articles may be randomly stored in any of the receptacles in any of a plurality of carriers. The system includes a polling and searching system operable to identify the carrier in which a requested article is currently stored, and a display system operable to display the carrier's location. A host computer controls the operation of the system, but no central data base is maintained of the coded articles.

Abstract: An apparatus for testing respective electrical components in situ within a circuit having a plurality of the electrical components. A power bus is connected between a power source and switching devices operable for conducting test current to respective ones of the electrical components. A comparator circuit includes inputs connected to the power bus and to a reference potential. A processor is programmed to actuate respective switching devices for causing a test current to be conducted from the power bus through a respective component, while sensing any output signal from the comparator circuit corresponding to an increased potential on the power bus indicative of a reduced current flow caused by an open or failed component.

Abstract: A multicolor display system comprised of a matrix of light-emitting diodes (LEDs). Each display dot or pixel is comprised of one red LED and one green LED. The display data is stored in a selected one or more discrete locations of a random access memory as a bit map, depending upon the desired display color. Each memory location is associated with a particular primary color "field" (e.g., red or green). The bit map indicates which of the LEDs is ON and which is OFF in order to display selected data. The data associated with each field is displayed sequentially during a display cycle so that the relative mixture of red fields and green fields determines the resulting display color. The duty cycle of each LED is therefore controlled in software, which reduces the need for complex hardware such as voltage drivers and counters needed in prior art multicolor display systems.

Abstract: A multicolor display system comprised of a matrix of light-emitting diodes (LEDs). Each display dot or pixel is comprised of one red LED and one green LED. The display data is stored in a selected one or more discrete locations of a random access memory as a bit map, depending upon the desired display color. Each memory location is associated with a particular primary color "field" (e.g., red or green). The bit map indicates which of the LEDs is ON and which is OFF in order to display selected data. The data associated with each field is displayed sequentially during a display cycle so that the relative mixture of red fields and green fields determines the resulting display color. The duty cycle of each LED is therefore controlled in software, which reduces the need for complex hardware such as voltage drivers and counters needed in prior art multicolor display systems.