Mac Museum – Installing Mac OS X 10.5 on below spec hardware

So as I mentioned in the previous post, I came in to posession of an old Apple Power Macintosh G4. Now, I already own a Mac Classic from ..what, the late 80’s? A-aand the G4 Cube. I like Mac design, and I’m not ashamed to admit it. I wouldn’t work with one (tried it, didn’t work for me), but they are crazy nice to look at. My plan is to have all of these installed with some version of Mac OS, and then shelve them/put them on display at home.

Yesterday i started with the Power Macintosh. I had a retail 10.5 DVD, so this was what i was going to try to install. There were some issues right off the bat. The 10.5 (Leopard) version of Mac OS X will only install on a 867 MHz (or more) processor, with 512MB RAM. RAM wasn’t an issue, the box came maxed out (?) with 1.5GB of it. But the CPU was going to be an issue.  I tried to install OS X as is, and it informed me pretty soon that my hardware was below the minimum specification. I would either have to go with 10.4, which i do not have, or…. figure something out.

After a bit of googling, I found that you could apparently boot into Open-Firmware (either by holding down cmd+opt+f+o and then powering on, or pressing the power button for a long time when booting until you get a tone), and then change an integer value that has the clock frequency of the cpu(s) in hertz. Don’t put in the install DVD before you’ve successfully booted into Open Firmware. Now, the relevant value was 450000000, which had to be changed to 867000000 (867 MHz, the minimum requirement of OS X 10.5 Leopard) with the following commands:

dev /cpus/PowerPC,G4@0 
d# 867000000 encode-int " clock-frequency" property 
boot cd:,\\:tbxi 

With dual CPU’s you’d rinse and repeat for G4@1. After typing each line, you should get an ok if the command was successfull. The last line tries to boot from the DVD. Next issue!

The drive included with the Power Mac would not boot the disk, so i had to change that out. Any standard IDE DVD drive would apparently work, i just picked one out from some spares i had. Hooked it up, jumpered it as master.

Ok, now, remember that the commands in Open Firmware are not persistent. They have to be input each time you boot, until you have the operating system installed. Once it’s installed, there are no more checks for clock frequency.

The next problem came with the hard drive. The Power Mac G4 that i have would not recognize certain drives, and apparently the limit is 128GB. I had a drive from an old DVR set-top box that i used, which had jumpers for “Capacity Cap”, which caps it at 128 GB at the drive level. That seemed to work fine, and the disk was recognized. I was able to continue installing…

..until the installer crashed. It gave me a page-long dump, and i was just about ready to give up. But, I decided to check all connections one more time, repartitioned the hard drive through the disk utility on the Leopard disk, input the Open Firmware magic one more time and this time it worked! The install took over an hour, but it worked. I was able to patch all the way to 10.5.8, and everything works, though it’s a bit slow of course.

The only thing i didn’t get working right off the bat was the wireless card in the G4. It saw the networks, and asked for the WPA passphrase, but after entering it, it would always turn up with “Connect Failed”. A colleague of mine suggested 10.5 might not have the correct drivers for that specific model of wlan card, which might be true. Also, i didn’t try it (yet) after the 10.5.8 update, so it might have been fixed. Other than that, it is working great.

Additional notes: Installing all the latest patches did not fix the WLAN issue. I’m unable to connect to my home network, which uses WPA2.

Power Macintosh G4 ripped open. Note the handy and modular design. Every part is accessible. Which can’t be said for modern Macs..

 

Next up? The G4 Cube, which, due to its William Gibson (Pattern Recognition) fame, and due to its unique futuristic/minimalistic look is my favorite out of all mac hardware! More on that tonight!

Sources:

http://www.thetechbuzz.net/2008/12/22/open-firmware-install-of-mac-os-x-105-leopard-on-unsupported-machines/

http://mac.linux.be/content/guide-open-firmware-apple-bios-0

http://en.wikipedia.org/wiki/Mac_OS_X_Leopard

Leave a Reply

Your email address will not be published. Required fields are marked *