Abstract: Method and apparatus for temporarily storing multiple data records in a data processing system which includes a host computer, a cache buffer subsystem, and a magnetic tape drive subsystem. A microprocessor, acting in part as a cache manager, directs the transfer of data into and out of a memory in the cache buffer subsystem by setting up a fill address register, a drain address register, and a start of record address register. Through utilization of a CRC byte to detect errors without correction, and a stop bit to locate the end of a record, values of the registers are compared dependent upon whether there is data being filled or drained to properly manage the temporary storage of data within the memory.