CP/M component that implements the file system and other services.

Basic Disk Operating System. The BDOS module of the CP/M operating systemprovides an interface for a user program to the operating. This interface is in the form of a set of function calls which may be made to the BDOS through calls to location 0005H in page zero. The user program specifies the number of the desired function in register C. User programs running under CP/M should use BDOS functions for all I/O operations to remain compatible with other CP/M systems and future releases. The BDOS normally resides in high memory directly below the BIOS.

Basic Disk Operating System. The core part of a simple operating system (e.g., PC-DOS). BDOS uses the BIOS to interface programs with the hardware. BDOS is by its nature machine-independent.