Disk First Aid is a free software utility made by which organzation, that was bundled with all computers running the classic Mac OS, this tool verifies and repairs a limited number of directory structure problems on any HFS or HFS Plus hard disk or volume?
HFS Plus HFS Plus or HFS+ is a file system developed by Apple Inc. It served as the primary file system of macOS. HFS+ was developed to replace the Hierarchical File System (HFS) as the primary file system used in Macintosh computers (or other systems running the classic Mac OS). It is also one of the formats used by the iPod digital music player. HFS Plus is also referred to as Mac OS Extended or HFS Extended, where its predecessor, HFS, is also referred to as "Mac OS Standard" or "HFS Standard". During development, Apple referred to this file system with the codename "Sequoia". At WWDC 2017, Apple announced macOS High Sierra, in which the default file system of Mac is changed to APFS.
PathMinder PathMinder is file manager software, or DOS shell originally designed for use under Microsoft's MS-DOS disk operating system. Published by Westlake Data Corporation of Austin, Texas, and designed by Albert Nurick and Brittain Fraley, it was first released on 30 September 1984 and became fairly popular. Although the user interface was composed of text characters, it had many graphical elements, especially when PathMinder Plus was released in 1989, and the Reconfigurable User Interface was introduced.