Abstract: A storage system stores information in the form of records each having a key portion and a data portion. These records are stored in key order. The records are stored in a shift register, preferably cyclic, access to the shift register being achieved through one or more ports in it. At each port there is a comparator for comparing a desired key with the keys of the stored records as they pass that port. On a successful comparison, a record may be read, extracted, or written. The system can cope with missing or duplicated keys, and records can be retrieved in sequential key order by simple sequential readout.