What Happened to CP/M (Control Program for Microcomputers)?
CP/M was the pioneering operating system for 8-bit microcomputers, dominating the market in the late 1970s and early 1980s. Its modular design made it highly adaptable, but it was ultimately displaced by MS-DOS after a pivotal missed deal with IBM for the original IBM PC. Today, CP/M remains a significant historical artifact, actively preserved and explored by retrocomputing enthusiasts through emulators and open-source projects.
Quick Answer
CP/M, or Control Program for Microcomputers, was the dominant operating system for 8-bit microcomputers from the late 1970s until the early 1980s. Developed by Gary Kildall of Digital Research, it set many standards for personal computer operating systems, including the command-line interface and file system conventions. Its decline began when Digital Research failed to secure a deal with IBM for the original IBM PC, which instead shipped with Microsoft's MS-DOS, a system heavily influenced by CP/M. As of 2026, CP/M is no longer in commercial use but thrives in retrocomputing communities, with various emulators and open-source initiatives allowing enthusiasts to experience and develop for the classic OS.
📊Key Facts
📅Complete Timeline15 events
CP/M Developed by Gary Kildall
Gary Kildall of Digital Research, Inc. creates CP/M (Control Program/Monitor, later Control Program for Microcomputers) for Intel 8080-based microcomputers, including the invention of the BIOS.
First Commercial Licensing
CP/M receives its first commercial licenses, notably with Omron of America and Lawrence Livermore Laboratories.
Becomes Dominant OS for 8-bit Microcomputers
CP/M becomes the most popular operating system in the nascent microcomputer industry, widely adopted across various 8080 and Z80 CPU-based systems.
CP/M 1.4 and 2.2 Released
Digital Research releases CP/M 1.4, followed by the highly successful CP/M 2.2, which becomes an industry standard and is sold on over 3000 different types of machines.
IBM PC Launches with PC DOS, Not CP/M-86
IBM introduces its Personal Computer with PC DOS (Microsoft's rebranded 86-DOS) as the primary operating system, after Digital Research and IBM fail to reach a licensing agreement for CP/M-86.
CP/M-86 Released for IBM PC
Digital Research releases CP/M-86 for the IBM PC, but its significantly higher price compared to PC DOS prevents widespread adoption.
CP/M Plus (v3.1) Released
The last 8-bit version of CP/M, known as CP/M Plus (version 3.1), is released, incorporating advanced features like bank switching memory management.
DR-DOS Introduced
Digital Research introduces DR-DOS, an MS-DOS compatible operating system, in an attempt to regain market share lost to Microsoft.
Digital Research Acquired by Novell
Novell acquires Digital Research, including all its operating system assets like CP/M and DR-DOS, aiming to compete with Microsoft in the networking and desktop OS markets.
Digital Research Assets Acquired by Caldera
Caldera acquires the remaining Digital Research assets, including CP/M and DR-DOS, from Novell.
CP/M Source Code Released as Open Source
The original CP/M source code is released under a BSD-like open-source license, making it freely available for study and non-commercial use.
CP/M's Legacy Highlighted in Tech Articles
Tech publications continue to publish articles detailing CP/M's historical significance and its influence on modern operating systems, emphasizing its role as the first popular microcomputer OS.
CPMDroid Z80/CP/M Emulator for Android Released
CPMDroid, a full-featured Z80/CP/M emulator, is released for Android devices, allowing users to run classic 8-bit CP/M software on modern phones and tablets.
Z80CPM Emulator for Windows Released
Z80CPM, a Z80 CPU emulator for running CP/M and classic 8-bit software, is released for Windows, offering RomWBW HBIOS compatibility and pre-loaded disk images.
CP/M-68K Ported to 80386 Protected Mode
A new project successfully ports CP/M-68K to the 80386 protected mode, demonstrating ongoing community interest in adapting CP/M to more modern architectures and expanding its capabilities beyond its original memory limitations.
Follow this story
Get an email when this timeline gets a major update.
🔍Deep Dive Analysis
CP/M, an acronym for Control Program for Microcomputers, emerged in 1974 as a groundbreaking operating system developed by Gary Kildall of Digital Research, Inc. for Intel 8080-based microcomputers. It quickly became the de facto standard for 8-bit machines, largely due to its innovative modular architecture, comprising the Basic Input/Output System (BIOS), the Basic Disk Operating System (BDOS), and the Console Command Processor (CCP). This design allowed manufacturers to easily adapt CP/M to their specific hardware configurations by only modifying the BIOS, fostering a vibrant ecosystem of compatible computers and third-party software.
The operating system's dominance peaked in the late 1970s and early 1980s, running on thousands of different machine types and supporting popular applications like WordStar and dBase. However, a critical turning point arrived in 1981 with the introduction of the IBM Personal Computer. IBM initially approached Digital Research to license CP/M-86, a 16-bit version of CP/M, but negotiations reportedly faltered over pricing and non-disclosure agreements. IBM subsequently turned to Microsoft, which acquired 86-DOS (a CP/M 'look-alike') from Seattle Computer Products and rebranded it as PC DOS for the IBM PC.
Although Digital Research eventually released CP/M-86 for the IBM PC in 1982, it was priced significantly higher than PC DOS (US$240 versus US$40), and Microsoft's system had already gained a substantial foothold. This strategic misstep proved fatal for CP/M's market leadership, as MS-DOS rapidly became the dominant operating system for the burgeoning IBM PC compatible market. Digital Research attempted to compete with its own MS-DOS compatible operating system, DR-DOS, which was often technically superior but struggled against Microsoft's market power.
Digital Research, along with its products including CP/M and DR-DOS, was acquired by Novell in 1991, and then later by Caldera in 1997. In 2001, the original CP/M source code was released under an open-source license, allowing for its preservation and continued study. Today, CP/M is primarily of historical interest, serving as a foundational element in the history of personal computing. Its influence on MS-DOS, particularly in its command structure and API, is widely acknowledged.
As of August 2026, CP/M continues to be a subject of fascination for retrocomputing enthusiasts. Various emulators are available, allowing users to run CP/M on modern hardware, including Android devices (e.g., CPMDroid released March 2026) and Windows PCs (e.g., Z80CPM released July 2026). There are ongoing community efforts to explore and port CP/M to new platforms, such as a recent project in August 2026 to port CP/M-68K to the 80386 protected mode, demonstrating a continued active interest in understanding and extending its capabilities. The open-source nature of CP/M allows for continuous community-driven development and preservation, ensuring its legacy endures.
What If...?
Explore alternate histories. What if CP/M (Control Program for Microcomputers) made different choices?