Patent US 4,130,867

One of a series of hardware/firmware instructions for converting a general purpose digital computer into a database machine by adding the capability of handling data base records. The invention comprises a hardware/firmware implemented machine instruction apparatus which fetches a record descriptor containing a referenced data base record type from main memory. The record type of the record to be checked, which is pointed to by a base register, is also fetched from main memory, and a comparison of the fetched record descriptor and type is made. A condition code is set to indicate the result of the comparison.