Data processing system and method of starting up system.

摘要

The data processing system has a <<basic>> or <<kernel>> instruction set stored in an auxiliary store (17) for transfer to the processor's control store (12) in start-up. The kernel instruction set is used to execute an initialization program which identifies an I/O device (16) in which a microcode local program and a desired microcode file are stored. No microcode load program is transferred to the processor's main memory (14) using the kernel instructions and the desired microcode file is then transferred in selected blocks from the I/O device (16) to the main memory (14) and there to the microcode control store (12). The microinstructions of the desired microcode file then can be used to load appropriate operating system software so that the overall processor is then ready for use in whatever applications are desirable.