System 7.0.1 was released months after the release of the original System 7 (System 7.0). It was mainly a bug-fix update. For Macintosh Portable users, the Portable and Brightness control panels were updated. Additionally, the Caps Lock extension, which showed an up-pointing arrow onscreen if the caps lock key was depressed on PowerBooks (for those laptops which had neither a depressed caps lock key nor a tiny light on the key), was introduced.