In the early 1980s, IBM management became concerned that IBM’s large number of incompatible midrange computer systems was hurting the company’s competitiveness, particularly against Digital Equipment Corporation’s VAX. In 1982, a project named Fort Knox commenced, which was intended to consolidate the System/36, the System/38, the IBM 8100, the Series/1 and the IBM 4300 series into a single product line based around an IBM 801-based processor codenamed Iliad, while retaining backwards compatibility with all the systems it was intended to replace. A new operating system would be created for Fort Knox, but the operating systems of each platform which Fort Knox was intended to replace would also be ported to the Iliad processor to allow customers to migrate their software to the new platform.
The Fort Knox project proved to be overly ambitious, and ran into multiple delays and changes of scope. As the project advanced, the requirement to support IBM 8100 and Series/1 software was dropped. When IBM’s engineers attempted to port the operating systems and software of their existing platforms, they discovered that it would be impossible without making extensive changes to the Iliad processor for each individual operating system – changes which the Iliad’s architects were unwilling to make. The proposed solution to this was to augment Iliad with operating system-specific co-processors which provided hardware support for a single operating system. However, the amount of logic needed in each co-processor grew until the co-processors became the main processor, and the Iliad was relegated to the role of a support processor – thus failing the goal of consolidating on a single processor architecture. The Fort Knox project was ultimately cancelled in 1985.
Source : Wikipedia …