The 74F433 is an expandable fall-through type high-speed First-In First-Out (FIFO) Buffer Memory that is optimized for high-speed disk or tape controller and communication buffer applications. It is organized as 64-words by 4-bits and may be expanded to any number of words or any number of bits in multiples of four. Data may be entered or extracted asynchronously in serial or parallel, allowing economical implementation of buffer memories.