Archive Corporation

Conner Peripherals, Inc.

Robert C Richmond

A buffered computer data storage tape controller having a microprocessor, a buffer memory, a host interface, an error correction circuit, and a tape drive interface. A host interface control program executed by the microprocessor controls the host interface for transferring computer data between the buffer memory and a host computer, and for receiving commands from the host computer. An error correction circuit control program executed by the microprocessor controls the error correction circuit for generating parity information for computer data stored in the buffer memory and to be written to tape, and for providing error correction for computer data storage read from tape and stored in the buffer memory for transfer to the host computer. A tape interface control program executed by the microprocessor controls the tape drive interface for transferring computer data between the buffer memory and a tape drive. The control programs are configured to suspend execution at predetermined suspend points and to continue execution at return points associated with said suspend points, and are executed sequentially in a concurrent manner by a scheduler program so that execution of the next control program in sequence continues when an executing program suspends. Interrupt routines executed pursuant to interrupts are provided for accomplishing tasks that have high priority.

Bufered intelligent digital tape controller with onboard ECC and

A method for monitoring the performance of a DAT drive and a method for self-cleaning the tape heads of a DAT drive pursuant to the occurrence of an error that could not be corrected by re-reads or re-writes. The monitoring method includes the steps of (a) reading a tape, (b) determining for each of successive groups of frames respective A track and B track reference error counts representative of the A track and B track C1 error counts in each group of frames, each group having the same number of frames, and (c) providing a warning signal indicative of degraded performance if (i) either the A track reference counts for a predetermined number of consecutive frame groups exceed a predetermined threshold or the B track reference counts for a predetermined number of consecutive frame groups exceed a predetermined threshold, or (ii) if both the A track and B track reference counts for the predetermined number of consecutive frame groups exceed the predetermined threshold. The self-clean procedure includes the steps of moving the tape to the end of the tape at a speed higher than normal, moving the tape to the beginning of the tape at a speed higher than normal, positioning the tape at the location of the error, providing a warning to the user, and resuming the operation that resulted in occurrence of the error. If the error persists, the user is notified of the occurrence of an uncorrectable error.

Method for self-cleaning dat drive tape heads

Raw error monitoring and reporting

A computer storage DAT drive which detects the form of a DAT tape and provides an audio signal output in response to an audio DAT tape. The drive rewinds the tape and then plays the tape at a speed that is about 5 to 15 times normal playback speed. During such playback, the tape length is determined and the subcode information is read to determine the format of the tape being played back. If the subcode tape format information reliably indicates the presence of an audio tape, the speed of playback is reduced to normal playback, and audio data interface circuitry is enabled for processing the audio data and providing an audio output signal to a front panel audio jack, for example. If the tape is not recognized as an audio tape within the playback of a predetermined length of tape, playback speed is reduced to normal playback speed and reading of the subcode information continues. If the subcode tape format information indicates that the tape is a computer data storage tape, the tape is read in accordance with the appropriate data storage format. Otherwise, the tape is determined to be blank or erased tape, and playback is stopped. A front panel eject pushbutton is utilized to provide basic controls for controlling the play of an audio tape, and front panel LEDs provide drive and cartridge status indications, including the presence of an audio format tape.

Audio tape operation on a DAT data storage drive

Apparatus and method for assembling data read from a data storage DAT tape into data groups. A tape data processing circuit responsive to the playback of DAT tape for provides for each frame a serial frame information output including a frame header and frame data, and an associated subcode information output, the subcode information output being available in advance of the associated frame information. A processor responsive to the subcode information checks the validity of the subcode information and determines the destination group memory locations of the associated frame data, such destination group memory locations being group frame locations specified pursuant to valid subcode information or temporary storage areas for frames having invalid subcode information. DMA circuitry transfers the frame data to the destination group memory locations. The processor further checks the error status of the stored frame data, verifies the group memory locations specified by the subcode information for frame data stored pursuant to valid subcode information, relocates frame data stored in temporary storage areas pursuant to frame location information contained in the frame headers under certain conditions, and updates a Bad Track Table to indicate the status of the received frame data stored in the group memory.

System for assembling playback data frames using indexed frame buffer

A technique for protecting the tape and mechanism of a DAT tape drive that includes engaging a PAUSE mode of operation, wherein the reel motors are off and the tape is stationarily positioned at a predetermined location, when the drive is not able to record or read a data group. If the amount of time during which the PAUSE mode is engaged exceeds a predetermined PAUSE mode limit, a STOP mode of operation, wherein the reel motors remain off and the pinch roller is disengaged from the tape and capstan, is engaged. If the amount of time during which the STOP mode is engaged exceeds a predetermined STOP mode limit, the tape is unloaded.

Growing community of inventors

Laguna Hills, CA, United States of America

Robert C Richmond