MAGNETIC TAPE CONTROLLER

PURPOSE:To confirm a block number and to recognize a correct block position by providing an area for storing data including the block number in a part of a data buffer. CONSTITUTION:In error recovery operation when an error is generated at the time of writing, writing data are stored only in a W part of the data buffer 5. When an error is generated in reading/postwriting operation after writing a certain data block, the reverse reading of a magnetic tape is executed. The read data are stored in the R part of the data buffer 5 and a block number part BNO is extracted from the data and sent to a microprocessor 9 to confirm whether block skipping is accurately executed or not.