 These file stores, a high maintenance item with pneumatic valves and other mechanical parts, were replaced in the 1980s with the 1A Attached Processor System (1AAPS) using the 3B20D Computer to provide access to the "1A File Store".The 1AAPS "1A File Store" is just a disk partitions in the 3B20D Computer.When the Common Network Interface (CNI) Ring became available it was added to the 1AAPS to provide Common Channel Signaling (CCS).