Abstract: A lapping apparatus of the "planetary" type that laps a workpiece to a true flat surface instead of to the domed surface characterizing the prior art: it includes a mechanism for spinning and orbiting the workpiece against a lapping disk that has a 360-degree mid-radial portion formed to abrade less rapidly than the radially inboard and outboard portions thereof. In one embodiment, the inboard and outboard portions of the disk are partly or entirely cut away (i.e., recessed) so as to present equal or smaller lapping surface areas than that of the mid-radial portion of the disk. In another embodiment, the abrading surfaces of the disk are formed as raised lands each of which has a shape derived as the mean length, at each orbiting radius, of the orbiting arcs that are swept by the disk across the workpiece while the workpiece is spinning through at least one full revolution. In another form, the lands are made narrower and more numerous, but have the same proportions along the various orbiting arcs.

Abstract: For a musical instrument, a fingering display apparatus that includes a number of electrical switches manually operable to designate a desired musical note, either alone or as the root note for a desired scale or chord. For each of the notes designated by the switches, means are provided to activate a sub-display showing all of the possible fingering positions for that note. If a scale or chord is designated, then all of the fingering positions for all of the notes of the entire scale or chord are displayed. One form of the display, using small electrical lamps, is mounted on the fret-board of a guitar.

Abstract: A tape transport front panel is adjustable to position the controls conveniently for operators in various positions.

Abstract: A latch for the pivoting head arm of a data-storage magnetic disc machine, in which a U-shaped latching member is arranged to avoid malfunctioning to block the movement of the arm, and may be operated entirely by means of a toggle spring, or entirely by means of a magnetic arrangement or cooperatively with both.

Abstract: A machine for extracting tape from a cassette and for threading the tape to a monoplanar disposition for longitudinal shuttling and transducing by fixed transducing heads, and then further threading the tape, if desired, to a helical disposition around a rotating head and scanning drum assembly without interrupting the longitudinal shuttling or transducing action.

Abstract: A tape cassette has a springloaded indexing mechanism to urge the cassette reels in a tape winding directions so as to tension the free run of tape between the reels whenever the cassette is removed from the tape transport machine.

Abstract: A tape transport of the U-coiling type having a takeup reel that rewinds in a clockwise direction is provided with a switch reversing this direction to anti-clockwise for rewinding a Z-coiled reel, and the switch is provided with a coordinating portion that clears the tape path only for the coiling direction that corresponds with the switch setting.

Abstract: An electroless plating bath tank with air sparging and bath heating attachments is provided with a workpiece rack on which multiple horizontal spindles bearing workpieces are rotated about their own axes while also being rotated eccentrically about a horizontal axis, so as to expose the workpiece more uniformly to the action of the bath.

Abstract: A magnetic tape transport has an improved capstan-tachometer construction and reel mounting arrangement.

Abstract: An encoder verifier checks the functioning of a Reed-Solomon encoder in which data and parity bytes are intended to be digitally encoded in data blocks to form for each data block a respective codeword in multi-bit bytes in the form of a Galois field polynomial that is divisible in the Galois field by a generator polynomial, such generator polynomial being the Galois field product of a plurality of factors. A Galois field polynomial divider divides respective codewords by one of the factors to produce a remainder signal systematically related to the remainder from such division. An indicator responsive to the remainder signal produces an indication of encoder malfunction when the remainder signal corresponds to a remainder other than zero.

Abstract: The trunnion bearing assemblies of a view finder for a television camera are provided with brake assemblies to hold the view finder in any chosen inclination or position, while yet permitting easy manual change of inclination and position. A pair of such brake assemblies may be arranged at the ends of an intermediate linking element to define with the camera and the view finder a Z-type configuration for extending the position and inclination ranges of the view finder.

Abstract: A high speed all digital detector for Class IV partial response signalling, particularly to such detector wherein the detector recorded signals are precoded, is based upon a recognition that 1-D.sup.2 filters correspond to a pair of 1-D filters responsive to alternate bits. A detector in accordance with the present invention includes a decision making circuit for maximum likelihood sequence estimation (MLSE) that has operated at a speed of at least 120 megabits per second. Such a detector makes decisions by comparing a current signal sample S.sub.n with a stored, or pointer, signal sample S.sub.p and the prior state (T.sub.IN) of the system. When a decision as to a current sample can be made, the decision is stored serially in a memory for later reading out as part of a completely detected stream. When a decision cannot be made as to a current sample, the current sample is stored with an indication of the position of that sample in the data stream.

Abstract: To measure the protrusion of a magnetic transducing head from a head-supporting and tape-guiding structure of the rotary drum-type, for example, a known gauge means is mounted on a base arranged to ameliorate excessive bearing pressure against the head and damage thereto and to the gauge apparatus.

Abstract: A shock absorbing fallfront bracket of the type having rigid hinged-together links diagonally supporting the fallfront panel in its open position and folding into the cabinet in closed position, and also including a third spring loaded link extending from the mutual hinge of the linked pair and to the cabinet to resiliently resist the full opening of the panel, and to fold, when closed, fully into the cabinet along with the supporting linked pair.

Abstract: A differential band brake is independently spring loaded at each end so that changes in the differential braking force ratio can be conveniently effected by changing to springs of different strength such as are readily available on the commercial market, rather than by changing the parameters of other portions of the apparatus of types not so readily available.

Abstract: A magnetic tape is guided past a transverse-scan rotating transducing head drum which is shaped to create an air bearing film between the drum and tape, so that only the tips of the heads themselves engage the tape. To avoid adverse influence on the air bearing, the guide means is arranged to engage the tape only at points remote from the plane of the head drum, and to induce at these points a transverse curvature in the tape that is of smaller radius than that of the head drum, ensuring that the tape rests closely on the air bearing across the entire tape width.