When a simple PC demo sparked the Mac's first multi-tasking revolution

In October 1984, Apple engineer Andy Hertzfeld witnessed journalist John Markoff using a DOS utility called "Memory Shift" on an IBM PC. This program allowed users to keep multiple applications resident in memory and switch between them with a keystroke. Hertzfeld, working on a scanner for the new 512K Macintosh, instantly realized the same concept could revolutionize the Mac, which at the time could only run one application at a time.

The moment of inspiration led directly to the development of Switcher, the Mac's first multi-tasking environment. This was a pivotal technical leap that expanded the machine's utility and helped define its future as a productivity platform. The story is a classic example of how observing a simple, clever solution on a rival platform can spark genuine innovation, changing the course of a product's evolution.