To run, CP/M must be loaded from the disk into memory. The ROM in a computer that uses CP/M need not be extensive. All the ROM needs to contain is a small piece of code known as a bootstrap loader (because that code effectively pulls the rest of the operating system up by its bootstraps). The bootstrap loader loads the very first 128-byte sector from the diskette into memory and runs it. This sector contains code to load the rest of CP/M into memory. The entire process is called booting the operating system.
