ADDRESS CONVERTING SYSTEM OF OVERLAY PROGRAM

摘要

PURPOSE:To realize a high speed for the conversion of a memory address, by converting the access address of a main memory into an address of a secondary memory only when an overlay area is executed and delivering the address of the main memory with no conversion when an access is given to the areas excepting the overlay area. CONSTITUTION:A register 1 sets a specific address of a main memory where the head address of an overlaying secondary memory is stored. The registers 3 and 4 set the head and final addresses respectively for the overlay area of the main memory. A register 2 sets the complement of ''2'' of the register 3. The corresponding information is informed and set to each of these registers 1-4 before the trace is started. In addition, a register 9 stores the head address of an overlay SM which is written onto the main memory which has the contents of the register 1 as an address. Thus the contents of the head display address of the overlay are rewritten thereafter by just setting the head display address of an overlay secondary memory as well as the overlay area. These rewritten contents are automatically stolen at the tracer side to perform an operation for conversion of an address.