Abstract: A parallel data bus tester is particularly applicable to SCSI type buses, and uses a plurality of comparator circuits to simultaneously examine the voltages present on the conductors of a bus cable. For twisted pair type conductors, the tester uses a high reference voltage, which is compared to the high voltage conductor of each pair, and a low reference voltage, which is compared to the low voltage conductor of each pair. The reference voltages are adjustable, and allow each reference voltage to be swept through the expected voltage range for its respective conductors. As the level of a reference voltage crosses that of a conductor voltage being examined, a comparator that receives the reference voltage and conductor voltage changes output state. This output is used to drive a corresponding LED assigned to the conductor in question. Thus, as the reference voltage, which is compared to each of its corresponding conductor voltages (i.e.

Abstract: An ink-jet type printer having a self-contained, unitary print-head and ink-supply cartridge which can be readily inserted or removed from the printer without requiring disconnection of or user-exposure to any part of the ink reservoir or ink delivery system. The large-capacity ink reservoir in the cartridge is separate from the ink delivery system and connected thereto by flexible hoses which allow the print-head to be moved independently from the ink supply. A drive gear for the print-head motion system, enclosed in the print-head and ink supply cartridge is partially exposed such that it engages a motor disposed within the printer housing when the cartridge is inserted into the printer housing. An elongated shutter mechanism in the cartridge opens during printing to expose the print-head to the printing surface. When the ink reservoir is exhausted, the cartridge is removed from the printer housing in a single motion.

Abstract: A paper handling apparatus 10 includes a plurality of paper receiving trays 12, 14, 16, 18 arranged vertically in close proximity to one another with a single paper feeding mechanism 20 provided to operate with all of the trays 12, 14, 16, 18. The paper feeding mechanism 20 moves vertically to selectively engage any selected one of the plurality of trays 12, 14, 16, 18. The vertical arrangement of the trays 12, 14, 16, 18 dictates that the trays are horizontally moveable between a first unselected position, where the trays are substantially vertically aligned with the one another, and a second selected position where the tray is horizontally moved to intersect the vertical path of the paper feeding mechanism 20. Horizontal movement of the trays 12, 14 16, 18 is effected by a single electric motor 28 rotatably attached to a shaft 30, which carries a series of gears 32, 34, 36, 38 that interact with a corresponding rack 40, 42, 44, 46 disposed on each of the trays 12, 14, 16, 18, respectively.