Abstract: A bar code (14) on an object (12) is read a distance from the object by a television camera. The output signal of the camera is thresholded to obtain a binary signal indicative of the image information associated with at least one scan line. This binary signal is written into a FIFO storage device (28) at a rate corresponding to the rate at which the camera images the bar code. Once the binary signal is fully written into the FIFO storage device, the binary signal is read from the FIFO at a second, much slower rate for decoding by a bar code decoder (36). In this way, the image of the bar code can be obtained by a television camera which is capable of imaging the bar code at a distance, while the image information can be decoded by a bar code decoder that operates to perform decoding at a rate much slower than the rate at which the camera acquires information.

Abstract: A crowd control barrier system is formed by regular barrier units interlocked end to end, with special wheeled units at intervals which provide elevated platforms for crowd surveillance. The special units can be converted to provide mobile storage racks for the regular units, which mobile racks can be wheeled onto a trailer or other vehicle for transportation and storage. The regular barrier units are formed of two continuous tubular members, one forming a frame for a vertical panel and one side of a base frame, and the other forming the other side of the base frame and vertical members welded to vertical portions of the first member to form vertical stanchions supporting the panel.

Abstract: A control circuit for a lightpen of a random scanning computer graphics sem (10) enabling the detection of lightpen interrupts or hits on contiguous vectors having drawing periods shorter than the response time of the lightpen (13). The lightpen interrupts are temporarily held in a peripheral circuit (31,32,34,36) and are selectively released to the computer system (via 29,21) at the end of its INTERPRET phase, i.e., at the end of a period during which the display processor decides how to handle the next display instruction. The present arrangement, which prevents the arrival of the lightpen interrupt signal during the INTERPRET phase, achieves a computer graphics system exhibiting maximum use of the information furnished by lightpen hits.

Abstract: A container particularly adapted for storing diskettes having an interior portion with a plurality of slots each adapted to receive a diskette to be stored. Indexing means in the form of a cam follower is adapted to move along a worm gear perpendicular to the diskettes within the holder. The cam follower sequentially engages during movement the stored diskettes and each engaged diskette is slidably moved out of alignment with the remainder of the diskettes to expose an edge portion thereof. The edge portion exposed has an indicia of identification, such as a tag or label, which is in this manner exposed for identification.

Abstract: A vector generator (11) for a computer graphics system of the type in which the beam (26) of a CRT (13) is deflected by analogue deflexion signals to form an image comprised of a plurality of discrete vectors each defined, in each of two, orthogonal deflexion axes, the first and second digital words respectively defining the initial position and the length of the vector. The vector generator (11) includes circuitry (43, 44) that ensures that each vector is drawn with substantially uniform brightness regardless of the length of the vector. Additional circuitry (42, 54) is furnished so that an instantaneous indication may be obtained of a light pen (19) strike or the occurrence of edge violations. This circuitry (42, 54) also yields continuous digital information concerning the current beam position.