System for assembling playback data frames using indexed frame buffer

Abstract

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.