Mac OS 7.5.4 or System 7.5.4 was a version of the Mac OS which reached Golden Master status and was slated to ship as an unified upgrade. However, just hours after it began to be seeded in September 1996, distribution was halted.
Mac OS 7.5.4 was released by Apple Inc. to a limited distribution, prior to an anticipated general release. Shortly after this limited distribution, it was discovered that some components had not been included in the installer..
Apple explains that Mac OS 7.5.4 was declared finished, and that distribution to seed sites actually had been initiated. However, an installer packaging issue was discovered, leading to the halting of distribution. Rather than having to struggle with two versions of Mac OS 7.5.4 (which was the case with Mac OS 7.5.2), Apple decided against the resulting confusion and revised the product version number to 7.5.5.
Minor revisions between Mac OS versions 7.5.4 and 7.5.5 are:
- IRTalk revision for the Macintosh Performa 5400 and 6400 families
- Virtual memory preferences and the chosen desktop pattern are saved when installing on the Performa 5400 and 6400 families
- The Energy Saver control panel underwent a minor revision