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Dual booting G4 from separate partitions?


Veteran Member
Mar 21, 2020
Now that I've "solved" the suicide battery on my dual G4, its time to get the operating system set up. Someone on here(wave if it was you) suggested doing separate partitions, one for OS9 and the other for OSX. I liked this idea so I did what any windows weenie would do - I zeroed the drive, then installed OS9 first on a partition consuming about half the drive. That part "worked" sort of(the install encountered a few fun problems), so I moved on to stage 2 and...

yeah. OSX did not "recognize" the empty second half of the disk. I mean it saw it, but would not let me make a partition. It just installed straight away to the existing partition. Good news is I've now got an OS9 system folder. But I really want to make that dual boot thing happen.

What is the secret?
Well I tried to take a mulligan, pulled the drive out, plugged it in via USB to a windows 10 PC. Figured "ok, Partition Magic does not see this hard drive, I'll just make a partition, then delete it".

That apparently did nothing. And I cannot work out how to boot to the install disks while there's an OS on there. Holding 'c' does nothing!
I am discovering this.

Silly question: is it possible to rename the partitions?

I've not got 2 partitions on there but the drive utility never allowed me to set a name. So they are "untitled" and "untitled2".
If you mean the name that is shown on the desktop, just click on the icon name once and wait until a text box opens around it and you can change the name. I think you can do it from the file menu also.
Holding down C to boot from disc should work (note that USB drives may or may not work). You need to do it as early as possible in the boot process - I usually have the key held down when I turn it on - and if the keyboard is connected through a hub or KVM, try connecting it directly.
What he said. C should boot to a bootable CD. Have you tried holding option? Hold down option until you see a list of drive icons. If the CD is bootable, it will show up on this screen too.
So holding down Alt worked. I had to attach a USB keyboard directly to the G4, press and hold Alt before hitting the power button(which is so odd to me and totally opposite of what you do with a PC) and that worked.

My main problem was the G4 is plugged in at the other end of the room and there's no possible way I can hit the power and reach the keyboard in time.
Now successfully dual-booting. I do have to use a second keyboard to reach OS9, but I'm not expecting to want to boot into it terribly often. The classic program found the OS9 system folder like a champ and I can now load classic software.

The Mac is now working exactly the way I want. Which means its probably time to put it in a closet and forget about it for another 5 years.
I would love to get my hands on a beige G3 someday. Did those come in a dual processor variant?

No. Apple's first forte into multi-processing machines was the 9600/200MP, but didn't release another dual processor machine until years later with the dual G4s.

And it wasn't really Apple that developed multi processor machines, it was third parties like Daystar with their Genesis MP that had up to four 604 processors. Had 3rd parties not developed multiprocessor machines, Apple would have never had them that early. A lot of the SMP code in Classic Mac OS was written by those third parties, because the OS didn't support multiple processors. And even with the SMP extensions, it wasn't very good because Mac OS up to that point was a cooperatively multitasked OS with no concept of memory protection, which is a requirement for SMP applications without ugly hacks.

IIRC, the SMP extensions allowed a round robin approach to multiprocessing, which wasn't very efficient, but allowed them to work within the limitations of classic Mac OS.
I'm guessing these are pretty rare these days?

The only thing better than 2 processors is obviously 4.

They were rare and hideously expensive when new. These days they're virtually unobtanium unless you have a Scrooge McDuck vault of money to burn.

They also really weren't that great, except in specific use cases. A single processor G4 would outperform a quad 604 easily. The quad 604 was hamstrung by the inefficient round-robin SMP, the slow 50 MHz FSB and slow memory. It's just a really expensive novelty.
A hideously expensive novelty that was only great in specific use-cases is my favorite kind of vintage PC. But it doesn't seem like I'll be tracking down a quad 604. Still fun to know such things exist.
Photoshop could use it, and that was the main usage case for MP

Mac users really liked to make their bank account suffer as much as possible. Before the dual and quad 604 machines, there were specialty NuBus accelerator cards for Photoshop that cost insane amounts of money.

Cards like that came back more recently in PCIe form, weird FPGA and ASIC accelerators for PS and some rendering software.
Cards like that came back more recently in PCIe form, weird FPGA and ASIC accelerators for PS and some rendering software.
Still a thing now with GPU rendering? Even if not I feel like I want one.

Photoshop users like that were professionals.
Keeping Adobe happy sold lots of Macs.
Good tools make professional users more money.
Better tools also have the advantage of being tax write-offs. Spending several grand on parts at the right time could easily net you significant savings on your taxes. Not so easy anymore but back in the day.

Also, loath though I am to admit it, in the PowerPC 604-era macs were better for image editing and whatnot than contemporary PCs. But I maintain the playing field leveled out sometime around the late 90s.