Abstract: Apparatus for monitoring, in real time, the I/O channel activity between a computer and a locally attached device. The apparatus does not interfere with the operation of the I/O channel while monitoring its activity and records events and sequences of events as they occur on the channel. An operator selects the events and sequences of events to be recorded and detected conditions are stored in memory. In particular, the apparatus only detects selected signals having a period greater than a predetermined value. If this occurs, the channel Tag and Bus lines being monitored are recorded in memory.

Abstract: In a matrix array liquid crystal display on silicon with an a.c. drive involving periodic reversal of the potential of the counter-electrode this reversal is liable to produce a significant r.m.s. error voltage at each reversal. The OFF element error voltage is effectively eliminated by blanking all picture elements at the commencement of each reversal, and the ON error voltage more evenly shared by making this reversal occur after a non-integral number of frame scans.

Abstract: A class of dyes is disclosed for use in smectic display cells which has the common feature of a strong absorption band registering with the emission line of a helium neon laser at 633 nm. The dyes have the general formula ##STR1## where X is an alkyl group or substituted alkyl group, and Y is an alkyl group, a phenyl group, or a substituted phenyl group.

Abstract: A flexible printed circuit is secured with adhesive to a glass or plastics substrate. Electrical connection between the tracks of the printed circuit and co-operating tracks on the substrate is made by way of conductive fibers with which the adhesive is loaded in such a proportion that no bridging electrical contact is established between laterally adjacent tracks.

Abstract: In a printer having a sheet feeder associated therewith, means are provided for feeding only the top sheet in a stack of sheets to the printer platen. A feed roller is positioned in contact with the top sheet and is energized a plurality of times prior to the paper clearing two corner separators associated with the sheet feeder, the acceleration and stopping of the feed roller having a tendency to jerk the first sheet of paper out of the stack while leaving the subsequent sheets in the stack. Although several methods can be utilized to energize the feed roller, control signals for energizing the feed roller are preferably generated by the printer microprocessor.

Abstract: A vacuum switch which is air operated and which has low contact capacitance, low inductance and low DC resistance. The switch has two fixed contacts and a moveable contact, the moveable contact being insulated from the moveable end structure to minimize coupling capacity between the two fixed contacts. A portion of the fixed contact support structure is cut away to minimize capacitance between the support structure and between the support structure and a ceramic body which is part of the switch vacuum envelope, the ceramic body insulating the contacts and the metal portions of the envelope.

Abstract: An internally electroded smectic liquid crystal display cell having a layer of a smectic material sandwiched between two electroded plates having electrodes that overlap at least in part wherein each said electrode is covered with an electrically insulating coherent layer whose surface has been treated to provide it with a rough texture provides a liquid crystal display cell of low voltage threshold characteristics.

Abstract: Apparatus used in conjunction with printer document feed mechanisms for allowing the dynamic adjustment of the feed mechanisms while paper feed is occurring, thus adjusting paper tension. The apparatus has a linear adjustment capability over its total range. In particular, adjusting levers are attached to the feed mechanism support shaft, pinions being attached to each end of the shaft. The pinion teeth mesh with the teeth of racks attached to each side plate of the feed mechanism. As the adjusting levers are moved, the support shaft and pinions rotate. The rotation of the pinion meshing with the rack causes the support shaft (and feed mechanism) to move, changing the distance between the feed mechanism and the printer platen. This distance, and paper tension, vary linearly with the angular position of the levers. The paper tension can be adjusted while the feed mechanism is operative.

Abstract: A sheet feeder for an impact daisywheel type printer is interconnected with an existing system by reconnecting the ASCII type data cable to the sheet feeder. The internal logic of the sheet feeder is cabled to the printer and provides for all necessary automatic control. The sheet feeder also includes a mechanical bail control which opens the bail to allow for automatic feeding of the paper around the platen.