On a lark, I dug my old Quad Power Mac G5 out and fired it up. After having to remove a bunch of dust from one of the temperature sensors which was causing the PCIe slots fan to run at full speed, it's all working! I reinstalled Mac OS X 10.4.8 from the original discs, and after restarting Software Update dutifully popped up, and man, those update sizes. So tiny! ðŸ˜
