System Enabler

A System Enabler is a small extension to classic Mac OS that was included with System 7.1 to Mac OS 8.1 to support rapid releases of new hardware from Apple Computer.

Description
In System 7.0.1 and earlier, releases of new Macintosh computer models often necessitated an updated build of system software. A System Enabler contains additional code needed to support new hardware features, allowing existing builds of system software to be released with new models. This became a necessity as many varying models were rapidly released during the Performa era in the 1990s. To reduce confusion, System 7.5 consolidated previous enablers into a single Universal Enabler. Subsequent major releases, such as Mac OS 7.6 and 8.0, incorporated such support for pre-existing models into the system software itself.

The use of System Enablers was phased out with the introduction of Macs with New World ROMs, in which the Macintosh Toolbox ROM contents were moved from the logic board to the startup drive, allowing for easier ROM updates. System Enabler 462, which allowed the first iMac G3 to run Mac OS 8.1, was the final release. By then, Apple co-founder Steve Jobs had begun greatly simplifying the Macintosh product line, and eliminating the reliance on enablers.