Adjusting Your Screen Size in Mac OS 9
TO ADJUST YOUR SCREEN SIZE IN MAC OS 9, (or earlier versions) click on the Apple Menu in the top left corner of the screen. From there, select Control Panels and then Monitors item and select one of the available resolutions.
Step 1: Call Up the Monitors under the Control Panel
Click on the Apple Menu, then select Control Panels and Monitors.
Step 2: Select a new Resolution