Data processor with improved subroutine control

Claim 1

IN AN INTERNALLY PROGRAMMED COMPUTER IN WHICH GROUPS OF PROGRAM CONTROL SIGNALS ARE STORED IN SEQUENTIAL LOCATIONS OF AN ADDRESSABLE MEMORY, APPARATUS FOR AUTOMATICALLY INTRODUCING STORED SUBROUTINES IN WHICH THE PROGRAM CONTROL SIGNALS FOR EACH SUBROUTINE ARE STORED IN SEQUENTIAL LOCATIONS OF THE ADDRESSABLE MEMORY STARTING WITH A DESIGNATED BASE ADDRESS LOCATION, SAID APPARATUS COMPRISING A PROGRAM REGISTER, A PROGRAM FETCH COUNTER, MEANS INCLUDING THE COUNTER FOR TRANSFERRING GROUPS OF PROGRAM CONTROL SIGNALS IN SEQUENCE FROM THE MEMORY OF THE PROGRAM REGISTER, A TEMPORARY STORAGE FACILITY INCLUDING A PLURALITY OF ADDRESSABLE STORAGE LOCATIONS, FIRST AND SECOND REGISTERS AND A BIDIRECTIONAL ADDRESS COUNTER FOR SELECTING THE STORAGE LOCATIONS IN PREDETERMINED SEQUENCE, FIRST CONTROL MEANS WHEN ACTIVATED TRANSFERRING A GROUP OF SIGNALS FROM THE FIRST REGISTER TO THE SECOND REGISTER, TRANSFERRING A GROUP OF SIGNALS FROM THE SECOND