Abstract: A method and apparatus which first calculates track to track skew in a tape device and then uses the results of that calculation to adjust the windows for detection of sync and resync characters. The system makes use of global circuitry which adjusts the sync and resync windows for all tracks based upon the skew calculation. In the case of the windows used for detecting resyncs, when skew is determined to be large, the global resync window must span a larger time period to account for the skew in detecting resync marks. Conversely, when there is little or no skew present, the windows for resync detection can be narrowed. Normally, the track logic utilizes its own local windows to detect resyncs. If a track misses a resync, however, it must use the global resync window to determine the next resync location. Once the tracks are resynchronized, control can return to local track circuitry to maintain synchronization.

Abstract: A drilling tool for drilling a curved hole. The tool includes a curved guide tube for positioning the tube in drilling position against a wall and a flexible shaft extending through the guide tube having a drill bit on the end thereof adjacent the outlet end of the tube and a shank on the opposite end engaged in a drill tool chuck. Operation of the drill tool rotates the drill bit and the tube guides and directs the bit to drill a curved or angled hole. The drill bit can be a spade bit, a spiral bit or a ball mill.

Abstract: A data storage system has error detecting and correcting system having three error codes. The data are arranged logically as a three-dimensional array consisting of a plurality of logically rectangular blocks of data. Each block of data has columns and rows of data. A first error code that corrects errors creates a first redundancy in each of the columns. A like-positioned block row of data in each of the blocks constitutes an array row of data. The array rows are grouped into sets of array rows, the number of array rows in each set vary inversely with a number of tracks of a record medium that concurrently receive the data for recording. Each set of data are recorded serially by bit in respective tracks of the tape record medium. Before recording, the block rows are logically rotated (end-around shifted) within each of the array rows.

Abstract: A method and apparatus which first calculates track to track skew in a tape device and then uses the results of that calculation to adjust the windows for detection of sync and resync characters. The system makes use of global circuitry which adjusts the sync and resync windows for all tracks based upon the skew calculation. In the case of the windows used for detecting resyncs, when skew is determined to be large, the global resync window must span a larger time period to account for the skew in detecting resync marks. Conversely, when there is little or no skew present, the windows for resync detection can be narrowed. Normally, the track logic utilizes its own local windows to detect resyncs. If a track misses a resync, however, it must use the global resync window to determined the next resync location. Once the tracks are resynchronized, control can return to local track circuitry to maintain synchronization.

Abstract: A seat back adjustment unit including a seat attaching plate which is fixedly secured to the seat of a chair and a back mounting plate which will have mounted thereon the customary seat back. The seat attaching plate has an upwardly and rearwardly curved portion on which there is mounted an adjustment unit. The adjustment unit in turn carries a lower generally horizontal portion of the back mounting plate. The adjustment unit includes a housing which is guidedly mounted on the curved rear portion of the seat attaching plate while the same housing has guidedly received therein the lower portion of the back mounting plate. The adjustment unit includes within the housing thereof a reduction gear drive unit which includes two driven member interlocked by pin and slot connections to the seat attaching plate and the back mounting plate for selective relative movement between the plates and the housing of the adjustment unit.

Abstract: A toy simulating a typewriter for enabling a child to compose a large number of sentences from a limited number of words, the toy having a keyboard with a plurality of keys, each key having a word imprinted thereon. A carriage is provided with paper receiving imprints of the words from hinged type arms operable upon depression of the keys, depression of one of the keys performing the imprinting operation and release of the key actuating a spacer frame coacting with an indexing bar for incrementing the carriage under force of a spring a predetermined distance.