Over the many years Apple Computer have been in operation, they have made a success of nearly-seamlessly transitioning multiple times between both operating systems and their underlying architecture. There have been many overlapping versions, but thereβs always a point at which a certain OS wonβt run on newer hardware. Now [Jubadub] has pushed one of those a little further than Apple intended, by persuading classic Mac System 7 to run on a G4.
System 7 was the OS your Mac would have run some time in the mid β90s, whether it was a later 68000 machine or a first-gen PowerMac. In its day it gave Windows 3.x and even 95 a run for their money, but it relied on an older Mac ROM architecture than the one found on a G4. The hack here lies in leaked ROMS, hidden backwards compatibility, and an unreleased but preserved System 7 version originally designed for the β90s Mac clone programme axed by Steve Jobs.Β Itβs not perfect, but they achieved the impossible.
As to why, it seems thereβs a significant amount of software that needs 7 to run, something mirrored in the non-Mac retrocomputing world. Even this hack isnβt the most surprising System 7 one weβve seen recently, as an example someone even made a version for x86 machines.
Thumbnail Image Art: Apple PowerMac G4 by baku13, CC BY-SA 3.0