Digital Research - CP/M-86 and DOS

CP/M-86 and DOS

When the IBM Personal Computer was being developed, DR was asked to supply a version of CP/M written for the Intel 8086 microprocessor as the standard operating system for the PC, which used the code-compatible Intel 8088 chip. DR, which had the dominant OS system of the day, was uneasy about the agreement with IBM and refused, Microsoft seized this opportunity to supply the OS in addition to other software (e.g. BASIC) for the new IBM PC. When the IBM PC arrived in late 1981, it came with PC-DOS, which was developed from 86-DOS, which Microsoft acquired for this purpose. By mid-1982, it was marketed as MS-DOS for use in hardware compatible non-IBM computers. This one decision resulted in Microsoft becoming the leading name in computer software. This story is detailed from the point of view of Microsoft and IBM in the PBS series Triumph of the Nerds and from the point of view of Gary Kildall's friends and coworkers in The Computer Chronicles.

Digital Research developed CP/M-86 as an alternative to MS-DOS and it was made available through IBM in early 1982. DR later created an MS-DOS clone with advanced features called DR-DOS, which pressured Microsoft to further improve its own DOS. The competition between MS-DOS and DR-DOS is one of the more controversial chapters of microcomputer history. Microsoft offered the best licensing terms to computer manufacturers that committed to selling MS-DOS with every processor they shipped, making it uneconomical for them to offer both systems. This practice led to a 1994 government antitrust lawsuit against Microsoft that barred it from per-processor licensing. DRI (and later its successor Caldera, Inc.) accused Microsoft of announcing vaporware versions of MS-DOS to suppress sales of DR-DOS. Microsoft refused to support DR-DOS in Windows; in one beta release of Windows 3.1, Microsoft included code that detected DR-DOS and displayed a warning message. However this code was not included in the final version of windows 3.1. It is said that other versions of Windows deliberately crashed the system if DR-DOS was detected so as to give the impression that DR-DOS was unstable. These activities came to light when the discovery process of the subsequent lawsuit uncovered emails from senior Microsoft executives that showed this time bomb plant was part of a concerted program to drive DRI out of the PC operating systems business. DRI's successor Caldera raised these disputes in a 1996 lawsuit, but the case was settled without a trial. As a condition of the settlement Microsoft paid Caldera $150 million ($222 million in present-day terms) and Caldera destroyed all documents it had produced in connection with the case. Although a costly settlement to Microsoft, this eliminated the most damning evidence of Microsoft's anti-trust behaviors, and allowed Microsoft to control and dominate this sector of the marketplace without concerns about any further serious competitor.