A couple months ago, I came across an old Macbook (2006). It still worked, but... It would serve better as a Raspberry Pi laptop. The goal of this project is to convert it to run on Pi, and to keep it as indistinguishable as possible from the original.
It's pretty obvious that the Raspberry Pi won't fit into the Mac's casing, so I'm going to be trimming it down. If you're interested in learning more about this process, you can look up 'diet pi' (or, of course, keep reading). Many online guides suggest desoldering the joints on the USB and GbE (gigabit ethernet) ports, but I found this was impractical, especially when I had a dremel sitting right there. This came with a cost, however: I broke a trace to one of the pads on a USB 3 lane because I wasn't careful enough.
I started by bending back the rear panels to make this as easy as possible. On another (less valuable) Pi I successfully removed half of one USB stack and relocated it. But on this one, I would be removing both. I got to work and soon had only 1 USB port. I removed the shielding on the GbE port only to find... ANOTHER PCB?? Apparently I didn't research this well enough, because in that chonky block there is a set of fragile magnetics... and I ruined them. So I set out to destroy the remains of this interface. Oops.
After that, it was a matter of getting a heatsink and some thermal paste to keep this bad boy cool.
IO, IO, it's off to work we go... Sorry. Really, I am.
Anyway, since I only have 1 4B, I need to get it into a functional state. This means it's IO time! The original side IO (and each's intended fate) will be listed here:
1. 1x Firewire: change to external HDMI
2. 2x USB ports: Use as... USB ports
3. 2x 3.5mm jack (mic and headphones): audio output
4. Charging port: charging! (this part is exciting)
5. Ethernet port: connect to Pi's GbE
6. mini-DVI: nothing, maybe a button
As you can see most of these things are well on toward their fates:
And I will be harvesting the original connectors for 3.5mm jacks, the USB, and the charging port.
The USB and 3.5mm ports are already hooked up, as well as the HDMI port. I made my own connectors by stealing ones from HDMI adapters.
Part of the goal of this project is to make it as indistinguishable from the original as possible - and that is why this is my favorite part. I took the guts of a USB charging brick and put them inside the Macbook charger - so now it outputs 5V and I can use the original magnetic connector. Apparently the LED on the power connector is controlled via 1-wire serial, but I've never used any kind of serial on the Pi before, so if anyone who reads this has any information, I would love to hear it.
The first step in this project was to be the screen. Without it, there could be no laptop, so it got priority.
I set off researching the panel that was in this model (the 2006). I found out it was the B133EW01 from Samsung (if I remember correctly). Armed with this information, I set off to find something that would drive it. Long story short, I found this: the T.SK105A.03. When it first arrived, I had my doubts. It looked pretty janky. But, after extracting the actual panel from the laptop, I was able to connect it - and it turned out that it worked pretty well. It has a small variety of inputs, including audio line in, HDMI, composite, and RGB video. Of course, some of those bulky connectors will have to go.
Here's it working with my Pi 2 over HDMI:
Eventually, lots of dremeling later, I got it somewhat trimmed down and sitting in the Mac chassis (and still working!) I routed the cables successfully up to the display assembly (in place of the old LVDS and inverter cables. Interestingly, there was originally a miniature inverter that lived in that little bump below the screen.
As you can see here, I moved the caps off of the PCB with some wires – for the sake of thinness. Not sure if that's a good idea, but it works...
The driver actually comes with a speaker header, but it's not great for the Mac's speakers. I know basically nothing about audio, so there's a good chance I'm damaging these speakers. Ah, well. My plan for the future is to get a USB audio interface that will include a microphone and a decent DAC (the Pi's is notoriously bad).
I came across this 2006 Macbook, and in typical hacker fashion immediately started disassembling it. I will note that while this is the first ever "MacBook" branded laptop, it's not Apple's first rodeo. But this was sort of the Wild West of laptops: in this era, we did not have the uniformity we enjoy today. The form factor as a whole was not as mature.
Consequently, the design was not today's (easy?) 'remove the backplate and you're in'. There is a cover in the (empty) battery bay that can be unscrewed to get at the 1GB of RAM, which is on two DIMMs connected to the mainboard. There are a myraid of screws to remove, but eventually, the keyboard+touchpad combo can be removed. Here's what it looks like:
It's fairly simple: hard drive, optical drive, mainboard, a small cooler. (And, of course, the hole for the battery compartment. The airflow would be directed out toward the screen, which I found interesting. It's another element of this laptop's design that is no longer used.
Well, as soon as I got it open it dawned on me that this wasn't helpful at all. I needed to test it, so I hooked the keyboard ribbon cable and plugged it in to a power adapter. It boots just fine, and after about 15 minutes of poking around in Apple's UI (ugh) I got to a terminal. But a Mac is not what we're here for, so it's so long to my little friend.