BATS II - A fast bubble automatic test system

A versatile, second generation bubble memory testing system (BATS II) has been built which is more than two orders of magnitude faster than our original BATS I bubble-wafer testing system. This minicomputer-based system allows arbitrary data patterns to be written and read, a large number of parameters to be varied, and a wide variety of error analyses to be performed. The speed of BATS II has been achieved by a very efficient combination of hardware and software. The bubble memory is controlled by a microprogrammed sequencer that runs ten data channels simultaneously. All read and write operations burst blocks of data under direct I/O from the minicomputer using alternate dual-channel DMA transfers and bubble memory reads interleaved with real-time error analysis. The system is designed for future operation of bubble memories at rotating field rates up to 600 kHz.