Hewlett-packard Company

Other

Mark E Nash

Jeffrey D Schwartz

John K Moore

Kevin L Miller

Steven Frederick Liepe

Kenneth G Richardson

Mark J Jedrzejewski

Ronald R Kennedy

Stephen G Uhlmann

Erik R Habbinga

Mark E Mills

Mark Millican

A vehicle mounted loading and unloading apparatus is provided which has a stationary mounting rack removably attachable to a roof of a vehicle and a top rack that includes a container for storing cargo, such as bales of hay. A moving mechanism is provided to move the top rack relative to the mounting rack from a transporting position to a loading/unloading position in which the top rack is lowered behind the vehicle to facilitate loading cargo. The top rack is guided from the transporting position to a loading/unloading position by a track structure extending from the mounting rack, which cooperates with a bearing structure fixed to sides of the top rack. A movable shelf may be provided on the top rack for assisting with loading and unloading cargo. The shelf is slidable between a rear end of the top rack and a front end of the top rack for placing the cargo.

Vehicle mounted loading and unloading apparatus

A method for reliably measuring preformatted servo patterns, on a magnetic tape, for positioning a magnetic head. The tape has constant frequency stripes marking servo pattern areas. The drive reading the preformatted tape has a read channel amplifier with automatic gain control (AGC). When a stripe is detected, AGC is enabled. Before leaving a stripe, AGC is placed on hold. The amplitudes of two servo bursts are then measured with a gain that has been calibrated by a signal from a stripe. During the time AGC is enabled, the amplifier peak output is limited to less than half the maximum amplifier peak output. The servo pattern signal amplitude is about twice the signal amplitude of a stripe, so that servo patterns are measured with almost the maximum signal-to-noise ratio. When a stripe is detected, a counter counts pulses resulting from the stripe signal, for a fixed time, to ensure that the stripe detection is valid. If the stripe is qualified, the servo pattern measurements are used for head alignment adjustment. If the strip is not qualified, the servo pattern measurements are discarded.

Accurate measurement of preformatted track servo patterns by a magnetic

Firmware updates for embedded systems are accomplished by using PROM in favor of conventional ROM, dividing the PROM into pages zero, one, two, etc., that can each contain an entire version of the embedded system. Pages of PROM are addressable by MSB address bits that originate from a circuit that selects page zero upon power-up, and that is responsive to a command in the firmware of the embedded system to increment the value of the MSB address bits. Upon initial fabrication, a product containing the embedded system has entirely unprogrammed PROM. An initial embedded system is zapped into page zero when the product is tested after being turned on for the first time. Replacement versions can be zapped into successive pages as the need arises. Each version includes an initialization routine and its own Get Next Page (GNP) bit. If a version is superseded by another, the old version indicates this by a GNP bit that gets programmed on the old page at the same time the replacement version is zapped into the new page. When that GNP bit is checked by its initialization routine the page selecting MSB address bits are incremented and the micro-processor executing the embedded system is reset; it now runs the initialization routine of the replacement version on the next page, which if not itself replaced, eventually branches out of the initialization routine to the main code of the replacement embedded system.

Method and apparatus for firmware upgrades in embedded systems

A method of calibrating signal processing circuitry in a magnetic data storage device. The method ensures that an adequate signal-to-noise ratio is achieved when reading a head-position calibration signal. First, discrimination thresholds are set to an initial low value. Then, with wide bandwidth and stationary media, amplifier gain is calibrated by adjusting gain to make the amplitude of amplified background noise equal to the initial threshold value. Finally, bandwidth is reduced and the discrimination thresholds are raised to a final value. The final threshold value ensures that a signal must exceed a predetermined signal-to-noise ratio before the signal is accepted as being valid.

Using read channel noise to initialize read channel for head position

A method and apparatus for using a varying amplitude data signal from a data storage medium such as a magnetic disk or magnetic tape to calibrate the gain of the data signal amplifier to an optimal fixed gain. At initialization, amplified data signal peaks are detected over a data region of the data storage medium. The amplified signal peaks are compared to a predetermined reference. The signal amplifier gain is adjusted until only a few amplified signal peaks exceed the reference. The amplifier gain is then fixed at the final adjusted value.

Using recorded data for auto calibration of fixed gain of a read

A tape drive control system with improved overall dam transfer rate. A streaming tape drive system for a multi-track serpentine data tape is controlled by a host computer. The data tape has a fixed number of data sectors per track. The host computer monitors tape position by observing data sector identification. The drive sends a ready/not-ready status signal to the host. The drive has a default mode. In the default mode, the drive generates an error signal if the host sends motor speed commands or head movement commands when the drive is sending a not-ready status. The host computer software can command the drive to enter a special mode. In the special mode, the drive does not generate an error if the host sends motor speed commands or head movement commands when the drive is sending a not-ready status. After placing the drive in the special mode, when the end of data for a track is reached, the host computer ignores the drive status signal and commands the tape drive to immediately set its motor to the maximum speed and to immediately move the head to the next track.

Tape drive fast seek to end-of-track

An apparatus and method for generating an index pulse by a data storage tape drive. The tape drive is controlled by a flexible disk controller. A multi-track tape is formatted into multiple data segments per track with erased areas between segments. A digital data signal from the tape signal processor is sampled to detect a lapse in data. Then, the analog data signal is continuously monitored to detect the reappearance of data. When filtered analog signal peaks exceed a fixed threshold, a pulse is generated from the tape drive to the flexible disk controller. In an alternative embodiment, to further protect against false triggering, index pulse generation is suppressed during most of each erased area between segments. In another embodiment, index pulse generation is suppressed if an erased area exceeds a length threshold, such as at the end of the tape. In still another embodiment, index pulse generation is suppressed if digital data reappears without triggering the analog monitoring circuit.

Index pulse generation in a data storage tape drive

A selectible computer tape drive activation and deactivation technique apparatus is disclosed. The invention integrates with existing floppy controllers in a manner which allows activation and deactivation of a computer tape drive without the need for select lines. The invention programs the floppy controller so as to generate an activation command which may be appended by an address to specify the specific drive involved. Both the command and the argument are chosen to be consistent with existing Quarter Inch Committee standards. With respect to the deselect method, additionally a failsafe, independent deactivation path exists to turn off the tape drive in the event any conflict in drive operations were to exist.

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Lyons, CO, United States of America

Mark E Nash