This is a free extension from Apple Computer, Inc. which corrects some problems with System 7.1 and 7 Pro and certain hardware configurations. Many people who have had trouble running Missions! on their systems have corrected the problem by installing this version of the HSU extension.
I have been given permission by an Apple Computer representative to distribute HSU v2.0.1 along with MotR, as long as the ReadMe file is also included. This will provide many people with a quick solution instead of having to contact me first. If you distribute MotR to others, you should include the HSU v2.0.1 folder and all of its contents.
HSU v2.0.1 is actually one part of a larger set of updates called System Update 2.0.1. The ReadMe file describes all of the individual parts, including HSU.
To install HSU v2.0.1, simply drag it into your Extensions folder. It should replace any older version you might have.