When the PowerBook 150 has an internal modem, the modem continues to draw power when not in use. This shortens battery life. Apple released the PowerBook 150 Update extension to correct this problem. The update extends battery life by reducing power requirements during sleep mode. It also fixes a potential system freeze problem that occurs when you use the internal modem several times without restarting the computer. If you have installed System 7.5 Update 1.0, you will no longer need the PowerBook 150 Update extension because the fix has been incorporated into the System 7.5 Update file. This file resides "loose" in the System Folder. The System 7.5 Update file contains the functionality of and removes the following extensions: EM Sound Update, PowerBook 150 Update, and Mount IDE Drive. Since the PowerBook 150 Update system extension is no longer needed, it is automatically removed from the Extensions folder (inside the System Folder) during installation of the System 7.5 Update 1.0.
