ibookmacospowerbook
I own a PowerBook G4 A1104 with 512 mb of ram and 1.5 ghz and I also own an Ibook G4 1.33 Ghz 512 ram. I have seen videos on youtube of people turning their ibook g4 and imac g4 into machines running from Yosemite to Sierra.
How can I accomplish this?
Leopard, 10.5, had some interesting features but I wouldn't recommend upgrading if you're comfortable with your laptop as is. There's a good chance that your iBook won't run 10.5.8 as smoothly as it does run 10.4.11. As far as I can tell, this is your only choice to upgrade because your iBook won't run 10.6 (Snow Leopard).
The only reason I can personally imagine wanting to upgrade is to get any security updates that were issued for the last 10.5 release (10.5.8) but weren't for 10.4.11. There were roughly two years in between the last Tiger release and the last Leopard release, but I'm not sure whether or not any security updates were released in that time.
A rewritten version of Firefox compiled to run great on older hardware.
We take the industry standard Mozilla Firefox browser and rewrite it to be compatible with Mac OS X 10.4 and 10.5, then compile it specially optimized for your G3, G4 or G5, add AltiVecTM JPEG, HTML and WebM decoding acceleration for G4 and G5 Macintoshes, and soup up JavaScript performance with our best-in-class just-in-time PowerPC script compiler. One of our four versions is just right for your particular Power Mac. And we keep it current, secure, and ready to rock.
Best Answer
Your Mac uses the PowerPC processor. Yosemite and Sierra require an Intel x64 compatible processor. So a software modification not practically possible. I can not directly answer the question regarding whether a hardware modification can be made. Although, I can say that usually such modifications require reusing the existing logical board, RAM and peripherals. The existing logic board, RAM and peripherals will be to slow for Yosemite and Sierra. Furthermore the video will not support the higher resolutions required by Yosemite and Sierra.
If you want to choose a current operating system, try Ubuntu (Lubuntu) or some other linux distro.