MacDraw Pro 1.5 is incompatible with the Radius Pivot software (version 1.1) under System 6.0.7 (gray scale or color Pivot monitor). When the text tool is selected and text is typed into any document, it may not appear on screen, and the system may lock up.
MacDraw Pro 1.5 seems to run fine with the Pivot monitors under System 7. Claris tested MacDraw Pro with Radius software 1.1. Radius tested MacDraw Pro with version 2 of the Radius software (Soft Pivot 2.0, Radiusware 2.2). (This version requires System 7).
If you're experiencing computer lockup or crash while running MacDraw Pro with the Radius software, try disabling as many startup documents / extensions as possible (other than the Radius software). If this does not fix the issue, try a complete reinstallation of the system software (trash the System and Finder from the hard disk, then reinstall the system software).