Abstract: Apparatus for enhancing the bit error rate performance of a storage medium, such as magnetic tape, magnetic disk, optical disk, or an equivalent thereof, includes two data transmission channels for recording in duplicate a stream of data bits corresponding to an information-bearing signal, each recorded bit stream being potentially influenced by a pattern of statistically distributed recording surface defects. During playback, error detection and correction circuitry for each channel provides an alarm signal synchronized with each uncorrected error condition in the corresponding stream of playback bits. A control circuit, responsive to the alarm signals from each channel, serves to interleave error-free bits from one channel, to the exclusion of error bits from the other channel, to provide a single continuous stream of relatively error-free bits corresponding to the information-bearing signal recorded.

Abstract: A helical scanning type magnetic recording and reproducing apparatus records a signal representing recording conditions on a magnetic tape when a recording is effected thereon, together with a PCM audio signal. At the time of reproduction, reproducing conditions are controlled so as to be the same as the recording conditions on the basis of the signal representing recording conditions reproduced.

Abstract: Digital data recorded in Manchester code in a 1553 MUX bus has the data portion of each word converted into NRZ-L format with the synchronization prefix or portion of each word converted into a corresponding NRZ-L formatted portion according to a predetermined protocol. The NRZ-L formatted word, prefix and data, is then converted into DM-M coded format. The Manchester code NRZ-L coded data is driven at a 1-MHz clock frequency, while the DM-M coded format is driven at a 500 kHz clock frequency. The data in DM-M code is then recorded on magnetic tape in a test recorder. The magnetic tape can be analyzed at a remote site after test by decoding the DM-M word into its corresponding NRZ-L word driven at the 1-MHz clock rate. The synchronization portion of the reconverted NRZ-L word is identified and the NRZ-L word correspondingly assembled into an output register according to a predetermined protocol.

Abstract: A video cassette recorder (VCR) erase protection system which is responsive to the standard anti-erase switch on a video cassette, is capable of "filling-in" unused portions of an erase-protected video cassette without disturbing previously recorded material on the cassette and without requiring the user to turn off the anti-erase switch on the cassette. By eliminating the need to turn off the anti-erase switch before recording additional material, the possibility of forgetting to later rearm the switch is eliminated. A microprocessor, responding to the anti-erase switch position and to the video signal sensed during an initial fast winding of the tape, intelligently positions the tape prior to recording so that recording takes place in unused tape portions only, without requiring any further action by the user.

Abstract: Block pattern detection circuitry for the read subsystem of a streaming tape drive system comprises a state machine, a pattern decoder, a tape mark detector, a block/gap filter, a block/gap meter, a verify count section, and a block read/verify section. The incorporation of a hardware state machine within the block detect circuitry permits the application of historical detect data in the interpretation of present detect data. This provides more certain pattern recognitions. Also, state data is fed back to the block/gap filter allowing precise block boundary triggers which are used by position capture circuitry and the drive controller to effect more precise re-try positioning. The use of the block/gap filter increases the detect circuitry's immunity to noise. The advantage is enhanced where the block/gap filter uses stochastic thresholding, which is also advantageously employed by the tape mark detector.

Abstract: Apparatus for processing vouchers includes a drive system suitable for causing a magnetic track on a voucher to pass over a magnetic head (170) which is connected to circuits for controlling writing and including a data transfer unit (22) and a data modulator (23). The stepper motor (185) has at least five phases, and the same clock (21) is used to control the stepper motor (185), the transfer of data from said unit (22), and the data modulator (23) in order to establish control transitions which are applied to the magnetic head.

Abstract: A video tape recorder for recording a plurality of skewed recording tracks on a video tape includes a recording head, an auxiliary head and an erasing head mounted on a rotary body of a tape guide drum about which the tape is helically wrapped, a rotary transformer for transmitting signals to the recording head, auxiliary head and erasing head rotating with the rotary body, an erase signal generator for generating an earsing signal to be supplied to the erasing head by way of the rotary transformer, and a short circuit arrangement coupled to a signal path connected with the auxiliary head for short circuiting the latter upon applying the erasing signal form the erase signal generator to the erasing head by way of the rotary transformer.

Abstract: In a multi-channel apparatus, a first plurality of N channels support user data and associated error correction and a second plurality of channels each contain a unique p-bit symbol followed by N consecutive M-bit samples of each of the N data channels. The receiver or retriever apparatus regenerates a system clock from all channels and examines the respective bit streams to score each bit phase as a match or a non-match of the sample in the synch channel with each M bit sample of the respective N data streams, and for each such N channels a counter corresponding to the then current phase is incremented or decremented. Relative skew for the N channels is derived from the addresses of the first counter to overflow for each of the N channels.

Abstract: In a tape signal copying apparatus in which signals recorded on a running mother tape are copied onto a running copy tape by urging the two running tapes against a tape guide member by air blown from an air blow-off slit and by applying a magnetic field or heat to the tapes, an air pool groove is formed in a wall of an air guide member at such a position as to face the tape guide member to further increase air pressure against the running tapes within an area where signals have already been copied. The higher air pressure elminates an offset in the mutual positional relationship between two tapes due to tape extension fluctuations, and therefore prevents a harmful influence such as demagnetization or thermal disturbance of other signals recorded on the mother tape upon signals already recorded on the copy tape, so that high level signals can be reliably copied between the two tapes.