CP/M-68K

Overview

CP/M-68K, also known as Control Program for Microcomputers-68K, is an operating system developed by Digital Research, Inc. for the Motorola 68000 family of microprocessors. The system was designed to provide a robust and flexible environment for software development and execution on 16-bit and 32-bit microcomputers. CP/M-68K is a derivative of the original CP/M operating system, which was widely used on 8-bit microcomputers in the late 1970s and early 1980s.

History and Development

CP/M-68K was introduced in the early 1980s as a response to the growing popularity of the Motorola 68000 microprocessor, which offered significant performance improvements over the 8-bit processors of the time. Digital Research aimed to leverage the success of CP/M by providing a similar operating system for the more powerful 68000 architecture. The development of CP/M-68K was part of a broader strategy by Digital Research to support a wide range of microprocessor families, including the Zilog Z8000 and Intel 8086.

Architecture

The architecture of CP/M-68K is based on a modular design that separates the operating system into distinct components. This modularity allows for greater flexibility and easier customization. The primary components of CP/M-68K include:

**BIOS (Basic Input/Output System):** The BIOS is responsible for interfacing with the hardware and providing low-level input/output functions. It is typically customized for each specific hardware platform.
**BDOS (Basic Disk Operating System):** The BDOS provides higher-level file management and disk operations. It offers a standardized set of system calls for file manipulation, device management, and process control.
**CCP (Console Command Processor):** The CCP is the user interface component of CP/M-68K. It interprets and executes user commands, providing a command-line interface for interacting with the operating system.

Features

CP/M-68K offers several features that make it a powerful and versatile operating system for the Motorola 68000 family of microprocessors:

**Multitasking:** CP/M-68K supports multitasking, allowing multiple processes to run concurrently. This is achieved through a preemptive scheduling mechanism that allocates CPU time to different processes based on their priority and resource requirements.
**File System:** The file system in CP/M-68K is hierarchical, supporting directories and subdirectories. It provides a range of file manipulation commands, including create, delete, rename, and copy.
**Device Independence:** CP/M-68K abstracts hardware devices through a standardized interface, allowing software to interact with different types of hardware without requiring specific knowledge of the underlying device.
**Memory Management:** CP/M-68K includes advanced memory management features, such as virtual memory and memory protection, to ensure efficient and secure use of system resources.

Software Ecosystem

The software ecosystem for CP/M-68K includes a wide range of development tools, applications, and utilities. Some of the key components of the software ecosystem are:

**Compilers and Assemblers:** CP/M-68K supports various programming languages, including C, Pascal, and assembly language. Compilers and assemblers for these languages are available, allowing developers to write and compile software for the operating system.
**Text Editors:** Several text editors are available for CP/M-68K, providing essential tools for software development and document creation. Popular text editors include ED and VEDIT.
**Utilities:** CP/M-68K includes a variety of utilities for system administration, file management, and debugging. These utilities help users perform common tasks and maintain the operating system.

Legacy and Impact

CP/M-68K played a significant role in the development of operating systems for the Motorola 68000 family of microprocessors. While it did not achieve the same level of widespread adoption as its 8-bit predecessor, CP/M-68K influenced the design of subsequent operating systems and contributed to the evolution of software development practices for 16-bit and 32-bit microcomputers.