I bought a Mac.

Yep. I regret to inform you all that, as of January 2025, I am a Mac user: I bought a Mac. I have betrayed the penguin.

Behold: My shame.

What?

Yes. The first Mac I have ever owned: this beautiful beast, a PowerMac G4 MDD: specifically a top-of-the-line dual 1.25 GHz FireWire 400 model circa 2002.

Here’s the full specs if you’re curious.

• 2x PowerPC 7455 G4 CPUs @ 1.25 GHz [Stock]
• 2GB (4x 512MB) DDR-333 PC-2700 RAM [Upgraded from 512MB]
• 512GB Lexar SSD + 750GB Seagate Barracuda (come back to) HDD [Upgraded from 1x 120GB 7200RPM HDD]
• ATI Radeon 9650 w/ 256MB of VRAM [Upgraded from ATI Radeon 9000 Pro w/ 64MB of VRAM]
• 1x CD/DVD-RW drive [Stock: CD-RW/DVD-R SuperDrive]¹
• It should be noted most of the stock specs are pulled from Wikipedia for reasons that will soon become obvious.²

So, how did such an icon of early 2000s Apple fall into my grubby hands? Well, it all started with the Wii U. I’m not joking.

For a while now, I have been working intermittently on the Wii U Linux kernel. In December, for reasons that aren’t important right now³, I turned my attention towards fixing KVM on the Wii U, but in order to fix it, I needed to figure when and why it broke, and the easiest way I could think to do that was with a PowerMac.⁴ Fortunately, my roommate already had a 233 MHz Bondi Blue iMac G3, which he very kindly agreed to lend me. However, when I tried to use it, it was so slow that I couldn’t even get Linux installed. After that, I decided I’d rather get crushed by a crane then do kernel debugging on a 233 MHz G3. I realized, somewhere, something needed a change.⁵

That’s when CursedSilicon⁶ stepped in.

He owned not one, but two PowerMac G4 MDDs, one of which he very kindly offered to sell to me for the low low price of $0 (plus shipping). Did I mention G4 MDDs are very heavy?

…

$91 and a few days later, the husk of a PowerMac was now under way. Yes, according to him, someone stole the RAM, hard drive, and PRAM⁷ battery out of the G4 before he shipped it to me! Apparently parts just… float around the hacker space he kept it in?! I had hoped they would turn up before he shipped it, but alas, they did not. Time to go internet spelunking.

COMPUTER REPAIR: THE GAME

You find yourself in a dark house. You search your person and find nothing but a debit card and a luminescent tablet. Staring into the ceaseless abyss, suddenly you remember: you have parts to acquire for your new computer.

LEVEL 1
HARD DRIVE

You already have several IDE hard drives in the garage, one of which you have previously tested and confirmed to be in good condition.

LEVEL COMPLETE

LEVEL 2
PRAM BATTERY

The PowerMac does not take a standard CR2032 coin cell; instead, it takes a 1/2 AA, which you never heard of before. What do you do?

> go to amazon

You find a 1/2 AA battery for $8. Seems like a little much, but this is kind of a specialty battery. What do you do?

> buy it

It will not arrive until after the computer. Fortunately, you do not need a battery to use the computer. You decide to install it whenever it shows up, and move on to other issues.

LEVEL COMPLETE

LEVEL 3
RAM

The PowerMac takes up to 4 sticks of standard PC-2700 DDR1 RAM, up to a total of 2GB. Perhaps once upon a time, you had some of this type of RAM, but if you did, it's long gone, and without it, you cannot use the computer. What do you do?

> go to ebay

There are many listings for DDR1 RAM on eBay, some of which are reasonably priced, while others are prohibitively expensive. You can't tell for certain whether any given set will work with your PowerMac. What do you do?

> im feeling lucky babyyyyy

You stumble upon a listing for lots of four 512MB non-ECC DDR1 RAM sticks. It seems perfect. Just one problem: they’re of “various brands”. You have no way of knowing whether the 4 you get will match. But you’re feeling lucky, so you roll the dice.

...

The sticks arrive just before the computer. You excitedly tear open the package and inspect them. To your delight, they’re a perfect match: 4 identical 512MB Kingston sticks. You step back and bask in the feeling that luck was on your side.

LEVEL COMPLETE.

The computer arrives. Hurriedly, you put in the RAM, plug in the power and video, and turn it on. You are greeted by a flashing folder.

You acquired: (1x) Working PowerMac G4 MDD.

Amazingly, I seem to have not taken a single photo during this entire process. In fact, I had to go back and get a photo of that screen for this post. It’s a well-worn stereotype that people of my generation are addicted to taking photos of everything and nothing, but clearly I do not fall into that trope. It’d be really convenient right now if I did, though.

The fun didn’t stop there though; it was just getting started! Because very quickly I realized why the PowerMac G4 MDD has a reputation as “the windtunnel Mac”: this thing is loud! Something which I was unaware of before buying it. By this point, however, I was in far too deep to turn back, so I needed to find a way to temper the beast.

I thought it would be easy: I’d just lubricate the ancient, notoriously loud system fan; except I came up with bright idea to take apart the fan so I could lubricate it properly. I then immediately snapped the clasp which held the rotor to the axle, killing the fan. And the worst part? Once it was dead, I discovered the system fan wasn’t even the problem: it was the power supply fans, meaning I wrecked the poor thing for nothing, and I now had a major problem I got to fix. sigh. Back to Amazon.

Fortunately, the G4’s fan was a standard size: 120mm, meaning I wasn’t totally out of luck. However, due to the MDD’s uniquely terrible thermal design, it requires a stupidly high flow rate fan to keep it cool, meaning I had to go out of my way to find one comparable to the behemoth I’d just destroyed. So, how much airflow did I need? According to what I read online, at least 80 CFM⁸.

For some reason, I decided to only look at Noctua fans, and their only 120mm fan that did at least 80CFM was the beefiest, fastest, and noisiest fan in their entire lineup: the 3000 RPM version of the NF-F12 Industrial PPC, moving 186.7 m3/h of air (109.9 CFM), and rated for 43.5 db of noise. Despite my concerns that it would be just as loud as the old fan, I bought it, alongside two 60mm fans for the power supply. In the meantime, I took to leaving the G4 open with a desk fan pointed at it so I could keep using it without it exploding.

Soon enough, my beautiful new tan-and-beige Noctua fans arrived, meaning it was time to install them, except this is an Apple product, so it couldn’t be that simple. Instead of standard 4 pin fan headers, the PowerMac G4 MDD uses 2 pin fan headers, meaning I was going to have to salvage the the old fans’ connectors. What could possibly go wrong?

I decided to tackle the system fan first. I felt I was desecrating a grave as I pulled out the remains of the original fan and snipped off the last few inches of its cable, then the end of the new fan’s cable. To connect them, I had the pleasure of dealing with heat shrink butt connectors! Why not use crimps? Because I didn’t have any in the right size. It was nerve-racking delicately torching the connector while trying not to burn myself or the cable, but I managed it. With that, operation number 1 was complete, leaving me with what I had been dreading: the power supply.

Now, electricity is not the boogeyman: you can open a power supply safely, you just have to be aware of the dangers inside. First, never open a running power supply: if you accidentally touch something at high voltage, you could die. However, even if you unplug it first, that doesn’t mean it’s safe because of these:

Capacitors.

Capacitors can hold charge for a long time, so no touchy. It probably wouldn’t kill you, because capacitors don’t actually store that much energy⁹, but that doesn’t mean it couldn’t kill you, so, no touchy!

That being said, I was likely never in any real danger, because by the time I opened up PowerMac’s power supply, it’d been unplugged for several hours, meaning the capacitors were likely already fully discharged. Still, I treated the capacitors as if they were charged, because, despite the state of the world at the moment, I do, in fact, enjoy being alive, and would rather stay that way.

But none of that mattered until I got into the dang thing, because it took me an embarrassingly long time to figure out how to open the power supply. (Turns out the top half of the case slides off once you take out all the screws. Who knew?) Upon doing so, I discovered that all of the wires inside, including the ones for the fans, were zip-tied together! Amazing! It was absolutely infuriating trying to maneuver a sharp instrument through the tight space and into the minuscule margin left by the factory on the zip ties, without breaking something. I was eventually able to shove the end of a pair of scissors through the loop of the tie, then twist until the plastic gave way, but it was such a pain. At least now, after a bit of unplugging and unscrewing, the old fans were finally free.

I then went through the same splicing process as the system fan for each of the 2 new power supply fans. But once that was done, the hard part was finally over, or at least I assumed. Unbeknownst to me, however, this computer had one last rage inducing quirk left in store for me: the new fan’s cables were too thick to fit. It took a good 10 minutes of me struggling to shove everything through before I was able to plug everything in and close the power supply. With that, at long last, the repair was complete; and all this over a broken sliver of metal.

I hesitantly took the PowerMac back upstairs, plugged it in, and pressed the power button. It turned on, but confusingly without so much as a peep from the fans; of course, just as I started to fear I’d somehow broken them, they whirred to life, and I soon discovered, to my horror, that my new Noctua fan was just as loud as the original when running at full blast, which it did, every few minutes, preventing me from falling asleep at night if I make the mistake of leaving it on. _{^{so worth it}}

And just as I had shut down the PowerMac and got ready to go to bed, I had one last devastating realization: I had once again gone about fixing the system fan in the dumbest way possible. Rather than using the extension cord that came in the box!!, I had spliced the cable directly off the fan. Instead of gaining the ability to easily replace the fan in the future if I should ever want to, for some reason, I had bound myself to use this poor, innocent Noctua fan in the G4 until it died, no matter what.

Oh, by the way, between when I bought the PowerMac and when it arrived, somebody else¹⁰ fixed the bug preventing KVM from working on the Wii U.
(ノಠ益ಠ)ノ彡┻━┻

┬─┬ノ( º _ ºノ) Well, guess I’m stuck with it now: gotta figure out what I’m gonna do with it. Oh wait, I already did, because this all happened 4 months ago; expect blog posts about what I’m up to on the G4 in the future. For now, that’s all I have for you. Working with this PowerMac has been equally fun and frustrating, ^{_{not to mention expensive}}, but it has been nice to play around with PowerPC Mac OS, and to experience what was once the bleeding edge of consumer computing. Besides, the thing’s beautiful: I mean, how can you not love this monstrosity?

Isn’t it glorious?

See you next time.
-Loganius. 🙂

Featured Macintosh image:
http://www.allaboutapple.com/, CC BY-SA 2.5 IT, via Wikimedia Commons
Star pattern added by Logan C.

1. I did not upgrade the optical drive. It came with a DVD-RW drive, despite Wikipedia saying the mid 2002 G4 MDD came with a DVD-R drive. Either Wikipedia is wrong, or someone already upgraded the optical drive in this G4. ↩︎
2. I’m referring to the fact that the G4 came with little more than the case, motherboard, and disc drive. ↩︎
3. There was talk among the kernel devs at the time about dropping support for KVM on 32 bit platforms altogether. That would have been horrible news for us in the PowerPC community, because the Wii, Wii U, and almost all PowerMacs are 32bit, so we concocted a plan to demonstrate as many use cases for KVM on 32 bit as possible, in the hopes of convincing the kernel devs to keep it around. However, before I could show KVM doing something useful, I had to get it doing something at all, hence: the need to fix KVM on the Wii U. ↩︎
4. The Wii U is a PowerPC machine; specifically, its CPU is a derivative of a derivative of a derivative of the PowerPC 750, also known as the G3. My plan was to bisect the issue using a PowerMac because they’re supported by upstream, and thus I could build and test any kernel commit using a PowerMac, whereas on the Wii U, I could only easily test full kernel releases ported to the Wii U. I probably could have found a way to test each individual commit on the Wii U if I’d had to, but I really didn’t want to. ↩︎
5. “Sadness is hanging there / To show love somewhere something needs a change, they need a change / THEY’LL NEED A CRANE” ↩︎
6. By the way, CursedSilicon has his own website which you should absolutely check out. It has more information about himself, his 2 PowerMacs (including the one I bought), his other projects, and all the other computers in his collection. ↩︎
7. As far as I know, PRAM is the PowerMac’s equivalent of CMOS: it stores firmware settings and the system time, except that PRAM does it in a much more structured and standardized way, to the point that 3rd party utilities can and do reliably modify PRAM. Also, in talking to CursedSilicon after it arrived (because that’s when I found out it had no PRAM battery), he told me it was likely removed by RePC before he bought it, rather than stolen, but small details like that can detract from the overall flow of the post: hence, rather than taking the time out of the main article to include them, I have footnotes. ↩︎
8. Cubic feet per minute. ↩︎
9. When I was preparing to swap out the fans, I actually calculated how much energy the capacitors inside the PowerMac G4’s power supply likely held. The 3 main power filtering capacitors (the scary ones) are each 100 µF, and at 170v (the peak-to-peak voltage of wall power here in North America), combined they hold about 4.5J of energy, roughly the amount needed to run a 40w incandescent equivalent LED light bulb for 1 second. Not that much energy. ↩︎
10. That somebody else was Anna Wilcox, proprietor of Wilcox Technologies Inc and lead developer of Adélie Linux. She had been contracted to fix KVM on PPC64, and had identified a bug caused by a change in GCC. It turns out bug also existed on PPC32, and was the cause of the issue I had been trying to fix. She was also in that thread about dropping KVM on 32 bit platforms I mentioned in footnote 1. ↩︎