reviving a G5

This has to be one of the more convoluted things I’ve ever done.

So basically it starts like this, I left my quad G5 mac in storage, some 1,600 miles away.  I wanted to see if I could get a cheap mac, and I managed to get a $100 mac out here in Vegas.  Part of the reason it was cheap is because the OS was screwed up.. You’d be surprised how many people ditch good machines, because the OS is messed up.

So I figure I’d just pop in a 10.4 or 10.5 DVD set and boot up, format and all will be well right?  Well it turns out the DVD drive doesn’t work properly.  And I don’t have any old ATA/parallel style DVD drives on me.  So I’ve basically got a $100 paper weight.

Until I decide to try something insane, so I get the great emulator PearPC, and install 10.4 into that.  Sadly PearPC doesn’t support raw disks, otherwise my original plan of popping in the disk to my PC, running PearPC and having it install to \\.\PhysicalDrive2 didn’t work so well.  But at least I could create a small install of 10.4.6 which will boot on a G5.

Next I dug out the ancient ancestor of all the hackintoshes, the deadmoo 10.4.1 image, and got it running on VirtualBOX (set the IDE to P3 mode, otherwise its SLOW!), after converting the raw 6GB image into a VMDK.  I then could use Qemu’s disk image conversion program to convert the 10.4.6 disk I installed with PearPC into a VMDK which I could then mount under the deadmoo image.

With that setup, I could then use the diskutil program on OS X deadmoo, and create a compressed disk image of the PowerPC 10.4.6 .  Then VirtualBOX will let you link to a physical drive, with a command something like this:

VBoxManage internalcommands createrawvmdk -filename drive2.vmdk
      -rawdisk \\.\PhysicalDrive2

With that done, I then could boot back into deadmoo with the G5’s disk attached, remove all the files/directories from the G5 disk (I didn’t format as I wondered if I format from an intel machine, would the endian be backwards making the filesystem unnecessarily slow?), doing the ‘repair permissions’ shuffle from the diskutil program, and then finally I could restore the PearPC compressed image of 10.4.6 onto the G5’s hard disk.

It worked.

Its a shame the PowerPC machines cannot boot from USB disks, otherwise there may have been an easier way…  Well that or order a DVD drive, but that’d take time…

So thankfully with emulation, disks that can work between machines, I was able to get the box up and running.

18 thoughts on “reviving a G5

  1. I have a lot of dead CD drives that like to behave odd. One thinks all the discs are blank or pretend it doesn’t have power, one can only read DVDs, not CDs, and a strange early ATAPI (I think it’s IDE, old PCs are made of 90% ribbon cables so it’s hard to tell) drive that doesn’t like burned discs, but that’s just early drives.

  2. Good work. I have a G3 machine without CD drive and was trying to do the same, but with PearPC and OS 9… gotta try with OS X Cheetah.

    • yeah OS X is the way to go, although I still think you need the drive already partitioned & formatted by a PowerPC Mac.. if my disk was blank I don’t think you can create a bootable PPC disk from an intel mac..

      • Well, with disk utility you can choose to partition with GUID , MBR or Apple partition table… isn’t it all you have to do to make a PPC disk bootable?

        • If I had more disks available I’d probably experiment, but I don’t. I also vaguely recall something about filesystems on intel being LSB, while on PPC being MSB. Sure they can read each others disks, but you don’t want your OS constantly bitflipping just to boot, that’d be silly. Also on the PPC there is a bunch of ‘hidden’ partitions for OS9 drivers, and some weird boot stuff that as a user you don’t see or interact with.. I’m pretty sure the intel macs don’t need any of that crap with their new fangled EFI BIOS, which from what I understand is similar to the old Amiga autoconfig, in which peripherals can provide EFI drivers on their own ROMS in a semi-sane manner, without partition trickery.

          But I could be all wrong.

          • To explain some more…

            GUID is for EFI-enabled machines.
            MBR is for Ye Olde Classic PCs.
            The Apple Partition Table format is in fact, for PowerPC Macs.

            Correct me if I’m wrong.

          • That is right, although I have to wonder will it boot…? If I had more disks handy I’d experiment, but I don’t.

            And I’m not sure about which byte order HFS stuff is stored in when its on PPC vs Intel. I’m sure OS X can deal with either, but I wanted to keep the PPC’s in the same order, which is why I basically rm -rf’d it vs letting it partition/format as the disk booted on the G5, and I didn’t want to make this thing into a toaster that quick.

  3. Oh, and one moar thing…

    I’m dumping out on my server, I’ll import it to a MediaWiki install once it’s finished if you want, or I’ll provide it to you.

  4. PowerPC machines can boot from USB. It’s just hidden and unsupported.

    Instructions on

    Mac OS X 10.4 was the first one including the USB mass storage drivers on the kernelcache file of installer media. Previous ones will simply not the root device.

    Somewhere in the G5 line USB support was added to the boot selector menu. My iMac G5 at least shows it.
    All G4s I’ve tested support the previously mentioned method (MDD, Mini, iMac, eMac, Tibook), dunno about G3.

    Apple contrary to other manufacturers use constant endianness for its filesystems. ProDOS is always little endian, even under Mac OS. HFS/HFS+ is always big endian, even under Intel Mac OS X.

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