System 7.5: Enhanced Large Volume Size Support

I understand that under System 7.5, the maximum hard drive volume size has been increased from 2 GB to 4 GB. How was this accomplished?
A set of modifications to the Finder and HFS were implemented to raise the maximum volume size of 2 GB to 4 GB. This was done by treating volume sizes as unsigned values. The exact upper limit is 4063 MB. System 7.5.2 (and newer) increases this limit to 2 terabytes on some computers, including:

It is not necessary to have SCSI Manager 4.3 installed to take advantage of the larger volume sizes.

Note that AppleShare, including Personal File Sharing, has its own volume size limitations. For more information, please see the following Tech Info Library article:

Article 15460: "AppleShare File Server: Chart Of All Limitations"
Published Date: Feb 19, 2012