System 4.3

System 4.3 (Finder 6.0, System Software 5.1) was a small update to the Finder. It added a new version of Apple HD SC Setup for updating the drivers on Apple-branded hard drives, and an updated LaserWriter driver.

Besides that, it is for all practical purposes identical to System Software 5.0. Some system version lists no mention to this release, implying that it probably replaced System 4.2 without much hype.