Editing Macintosh II (section)

=== Early Development (1985-1986) ===

The project emerged from internal tensions at Apple regarding the future direction of the Macintosh platform. While Steve Jobs had championed the original Macintosh's closed architecture and compact all-in-one design, a faction within Apple's engineering team, led by hardware engineer Michael Dhuey and project manager Brian Berkeley, advocated for a more expandable, modular system that could compete with IBM-compatible machines and high-end workstations from companies like Sun Microsystems.

Following Jobs' departure from Apple in September 1985, CEO John Sculley and head of engineering Jean-Louis Gassée greenlit the development of an open-architecture Macintosh. Gassée, who had previously worked at Hewlett-Packard, understood the importance of expandability in the business market and became the project's primary champion within Apple's executive team.

The development team faced numerous technical challenges, including:
* Implementing color graphics while maintaining compatibility with existing Macintosh software
* Designing a modular architecture that could accommodate third-party expansion cards
* Creating a system powerful enough to run complex professional applications
* Developing new ROM routines to support color QuickDraw and slot management