Abstract: The present invention is a system and method for detecting the presence of a cable in a connector. The system may comprise one or more of the following features: (a) a first circuit contact; (b) a second circuit contact; (c) a first capacitive element; (d) an electrical ground; (e) a voltage source; and (f) a logical output. The second circuit contact may be connected to ground. The capacitive element may be driven to ground by connection of the first and second circuit contacts to corresponding cable contacts.

Abstract: The present invention is a method and a system for dynamic mapping of a fiber channel loop ID in an ALPA loop. Based on reserved address information for the fiber channel system and a number of select ID bits for a slot ID, a dynamic drive mapping table is created. A unique address may be assigned to each drive and each controller in the ALPA loop. The created drive mapping table may be stored on logic decoding circuitry of an adaptor card coupled to each disk drive in the ALPA loop. When fiber channel loop ID signals are sent from a backplane, the fiber channel loop ID signals are translated into seven bits within an ALPA address range based on the dynamic drive mapping table. The converted signals may be sent to the disk drive coupled the adaptor card at boot up time.

Abstract: A source of light modulated by input data provides the modulated light to a phototransistor. A capacitor couples the emitter of the phototransistor to ground. A discharging transistor switch is coupled across the capacitor and a voltage comparator is coupled to the phototransistor emitter for providing a signal when the voltage across the capacitor exceeds a predetermined threshold. A microprocessor coupled to the comparator actuates the discharging switch in accordance with the comparator output.

Abstract: Fluorescent optical switch and keyboard apparatus wherein a plurality of fluorescent optical key switches are arranged in a matrix array of rows and columns with a key disposed at each column-row intersection and wherein each key carries a fluorescent optically reflective element thereon. A single optical photo-diode disposed at each key location is caused to operate in three discrete modes with respect to the fluorescent element. In one mode the diode emits light which is caused to be reflected upon key when the key is depressed. In another mode the reflected light striking the diode causes the diode to act as a photo-receptor effectively indicating key actuation.

Abstract: A multi-plane optical membrane switch for use for example in a keyboard matrix is formed by two flat, planar, clear, plastic members disposed in parallel, separated relationship and each having individual light conducting guides or channels thereon. The channels of the lower plane are disposed at right angles to the channels of the upper plane. The upper set of light guides includes integral, gently curving coupler taps disposed at the intersection of the upper and lower guides for coupling the light from the lower planar guide channels into the upper guide channels when the two channel intersections are pressed together by the key top effectively switching the light from the lower to the upper channels.

Abstract: Photo-optical switch apparatus useful for example in keyboard switches includes a photopolymerized orthogonal matrix of horizontal and vertical intersecting light channels or guides, monolithically formed by exposure to ultraviolet light on a flat planar, plastic substrate. Each intersection has a refractive index higher than either the channel or the adjacent substrate area. A curved tap or light coupler couples the horizontal to the vertical channel of the array. The intersections of the channels are disposed over an array of upstanding projections on a flat mounting substrate with each projection located at a respective intersection of the horizontal and vertical light channel. A light absorbing key pad is arranged adjacent to each intersection to couple light from the channel up into the key pad. A relative loss of light indicates the key being depressed.

Abstract: Molded optical waveguide switching apparatus wherein a flat, planar light transmissive plastic member of a refractive index N.sub.2 is premolded with orthogonally arranged obverse and reverse grooves or channels and wherein each such channel or groove is filled-in or molded with a light transmissive plastic of a refractive index N.sub.1 (where N.sub.1 >N.sub.2) effectively forming front and back light conducting channels or waveguides at right angles to one another on the flat planar member. A gently curved tap is molded into the intersecting area of each row and column waveguide with a through opening or aperture formed adjacent each intersection. The taps of the obverse side are curved downwardly to meet the upwardly curved taps of the reverse side of the planar member. Light blocking and unblocking members are operably disposed in respective apertures to interrupt light from light generating to light receiving receptors.

Abstract: The invention relates to photo-optical detection by coded aperture in which photo-optical keyboard apparatus includes a pattern arrangement of keys in rows and columns wherein each row is provided with a light source or generator optically couplable to a light receiver or receptor and including individual key stems each of which is provided with a light transfer attenuating, limiting or constricting element each element being arranged to pass or restrict a percentage of the light from source to receptor, key to key, by column to row effective to indicate the precise key position or location as a result of the actuation or depression of any key in the pattern arrangement. By electrically multiplexing the light signals a minimum circuit complex is required.