Copland

From Wikipedia, the free encyclopedia.

This article is about the Copland project at Apple Computer. For the American composer see Aaron Copland.
For the movie starring Sylvester Stallone and Harvey Keitel see Cop Land.

Copland was a project at Apple Computer to create an updated version of the Macintosh operating system. Begun in earnest in 1994, it was abandoned in August of 1996.

Contents

Background

In 1989, managers at Apple had a meeting to plan the future course of Mac OS development. Ideas were written on index cards; features that seemed simple enough to implement in the short term (like adding color to the user interface), were written on blue cards, while more advanced ideas (like an object oriented file system) were written on pink cards. Development of the ideas contained on both sets of cards was to proceed in parallel. The projects were known simply as "blue" and "pink". Apple intended to have the blue team (which came to call itself the "Blue Meanies" after characters in Yellow Submarine) release an updated Mac OS in the 1990-91 timeframe, and the pink team to release an entirely new OS around 1993.

The blue team delivered what became known as "System 7" only slightly late near the end of 1991, but the pink team suffered from second-system effect and continued to slip its release into the indefinite future. Eventually Apple semi-abandoned the pink project by spinning it off to form Taligent. This left Mac OS in a bad position. Originally intended to support a single user running a single application on a non-networked machine with a floppy disk for storage, many parts of the operating system simply did not scale well to the increasing demands of users. In particular the architecture of QuickDraw made it very difficult to introduce multitasking into the system, and the file system was particularly inefficient when used with hard disk drives.

Several attempts were made by various teams to address these issues with an updated operating system, but they ran afoul of internal politics and turf wars. John Sculley, Apple's CEO during this period, largely ignored managing of the company itself while he concentrated on sales and marketing. As a result the engineering departments had no clear direction.

Design

With System 7.5 released in autumn 1994, Apple management decided that the decade-old Macintosh operating system had run its course, and an entirely new operating system with more advanced features would be needed for the platform to compete with upcoming releases of Microsoft Windows.

The result was a next-generation operating system, code named "Copland" after composer Aaron Copland. Copland was to run Mac OS on top of a microkernel named NuKernel, which offered modern versions of Mac services such as the file system and networking. Programs written for the new system would run as first-class citizens, able to call other programs using high-speed interapplication communications to provide services. One important program was the blue box, which essentially encapsulated an existing System 7 OS inside a single process in a single address space. Older Mac programs would run inside the blue box, as "cooperative tasks" that used non-re-entrant Toolbox calls. The microkernel would isolate access to memory and thereby increase stability; if a new application crashed it simply needed to be restarted, and at worst a "classic application" would require the blue box as a whole to restart. The days of applications taking down the whole system would be over.

The trick was to make all of this fit into existing Macs. Running a number of copies of System 7 would simply not work due to its large size. Copland attempted to address this by introducing a large number of shared libraries and a fiendishly complex memory management scheme. It was intended that Copland would only be perhaps 50% larger than the existing Mac OS (now well into the 2MB range), a reasonable goal given the ever-increasing amount of RAM being incorporated into the average machine.

Another key feature of Copland was that it would be completely PowerPC "native." System 7 had been recompiled on the PowerPC with great success, but the system still relied on the processor looking like a member of the Motorola 68000 family. In particular the interrupt handlers in the Mac OS had to be emulated, requiring an expensive call into the OS to translate these to the PowerPC's much simpler system. Removing this limitation would allow Copland-native applications to run much faster, as much as 50% in many cases, with no special effort on the part of the developers.

Development

Parts of the Copland, most notably an early version of the new file system, were demonstrated at Apple's World Wide Developer's Conference in May 1994. Apple also promised that a beta release of Copland would be ready by the end of the year, for full release in early 1995, and that an even more advanced successor code-named Gershwin would follow in 1996. Throughout the year, Apple released a number of mockups to various magazines showing what the new system would look like, and commented continually that the company was fully committed to this project. By the end of the year, however, the developer release was nowhere in sight.

At WWDC '95, Apple's new CEO, Gil Amelio, talked exclusively about Copland, now known as MacOS 8, repeatedly stating that it was the only focus of Apple engineering. Amelio announced that it would ship to developers only a few months later at the end of the summer, with a full release planned for late fall. Very few demos of the system were actually shown at the conference. Instead what was demonstrated were various pieces of the technology and the user interface that would go into the system, such as a new file management dialog. Little of the technology of the core system was demonstrated; the new file system that had been shown a year earlier was absent here.

After a number of people at the show complained about the lack of sophistication of the microkernel, notably the lack of multithreading, Amelio came back on stage at the end of the show and announced that they would be adding that to the feature list. This implied that the system was nowhere near ready, as such a feature is so fundamental to a kernel that it would be impossible to add it so close to the shipping date.

In August 1995, "Developer Release 0" was sent to a small number of selected partners. But the system was so unstable that it was impossible to develop on. Far from demonstrating improved stability, it often crashed after doing nothing at all. In October, Apple moved the target delivery date to "sometime," perhaps 1997. One of the groups most surprised by the announcement was Apple's own hardware team, who had been waiting for Copland to allow the PowerPC to truly shine.

Cancellation

Later that summer the situation was no better, and Amelio realized something serious had to be done. He lured Ellen Hancock away from her management position at IBM to take over engineering and get Copland development back on track. After a few months on the job she realized the situation was hopeless; given current development and engineering, Copland would never ship at all. She suggested that development continue on the existing Mac OS to improve its stability, while looking outside the company for a new operating system.

In August 1996, just as "Developer Release 1" was being prepared, Apple officially cancelled Copland. Among the reasons given were the slow pace of development and the many technical problems remaining to be solved. Plans for Gershwin were also scrapped; development on Gershwin had not yet begun. Hancock noted that in discussions with developers it became clear there was no Copland/Gershwin plan at all, although everyone seemed to know that "Gershwin would be the fully modern Copland". In fact there was no one in the company that seemed to know exactly what that meant, and no engineering had been dedicated to producing it.

Following Hancock's plan, development of System 7.5 continued with a number of technologies originally slated for Copland being rolled into the base OS. These included themes and drag-and-drop text. Eventually they released a number of such upgrades as Mac OS 8, in order to deliver on their promise of having something called Mac OS 8 running on all existing machines and thereby avoiding a lawsuit.

At the same time, Hancock's other plan was also followed, and Apple started looking for a third-party product to buy. After lengthy discussions with Be, many were surprised when Apple bought NeXT Computer in December 1996. The project to port OpenStep to the Macintosh platform was named Rhapsody and was eventually released as Mac OS X, which also uses the "blue box" concept to run applications written for older versions of Mac OS.

See also

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