Arrangement for retrieving information recorded on a semi-random access record carrier

Claim 1

In a data processing system having a microprocessor for processing microprograms and a record carrier for storing records and index key words associated with the records, a record retrieval means controlled by said microprocessor for retrieving the records from said record carrier comprising: comparing means for comparing in succession the index key words stored on said record carrier with a search key word provided by said microprocessor to indicate whether an index key word matches the search key word; identifying means connected to said comparing means for identifying the position on said record carrier of the index key word which matches the search key word, wherein said microprocessor comprises record address calculating means responsive to the output of said identifying means for calculating the address of the record associated with the index key word which matches the search key word from the position on said record carrier of the index key words; and accessing means controlled by said microprocessor for accessing the record on said record identified by the search key word.