There are two main emotions that drive my creativity: spite and hilarity. This project has captured both. Hilarity is what has kept me from getting rid of the 2010 15" Macbook Pro I'm typing this on now, my daily-driver computer for the entirety of my middle and high school years. Through careful upgrades and attentive software tuning, I've kept this old computer working smoothly for several years. I can even play some new video games on here! I was convinced that, because of hilarity alone, this would be the computer I took to college.

Until, a few months ago, my soon-to-be roommate messaged me on Discord to flex his new laptop, the ROG Zephyrus G14. Complete with the latest in computing technology, it blew my old Macbook out of the water no matter how carefully I arranged my system. Immediately, I knew what I had to do. In purchasing that laptop, he sold a desktop PC he has been using for a few years. His biggest boast about his PC was his ultra-wide monitor—a feature nowhere to be seen on his new laptop. It was time for me to best him at his own game. It was time for me to build a triple-monitor laptop.

Spite and hilarity, a perfect combination.

I already had my eyes on the chassis of that old Powerbook, mostly with the intention of turning it into a Raspberry Pi machine or something, but this was a better excuse. I took it apart, careful to keep the original parts intact.

Looking at the inside with the keyboard off. From the left: 500MB hard drive, 33MHz processor, floppy drive. The internals that are beneath were the keyboard was are surrounded by an aluminum frame. The area under the trackpad and palm rest is populated by two battery bays, with no aluminum frame.

A closer look at the inside. The hard drive and floppy drive have been removed.

I managed to get every piece of electronics out of the case without breaking a thing, and was left with a considerably spacious and geometrically non-confusing interior. Next, I started hunting for parts. The internals can be divided into four main categories, which I'll explain independently: computer, display, power, and cooling.

Finding the Right Computery Bits

Because nobody really builds custom laptops, I knew building a computer powerful enough to fulfill my triple-monitor dream was a tall order. I started my search by looking at the easy option: prebuilt, tiny computers. I found a few I liked, like:

The Raspberry Pi 4 Model B is a blisteringly powerful computer for its price range, and really caught my eye at first. For $35, absolutely nothing would come close to this.

It was around this time that I decided I shifted my goal to booting MacOSX on this old computer. That meant a computer with an Intel CPU.

The LattePanda Alpha 864s has a similar shape to an RPi, but far more powerful and with an integrated cooling fan.

The UDOO x86 Ultra is sort of an in-between of the Raspberry Pi and and the LattePanda. More affordable, but not as powerful.

Just on a whim, I decided to find out whether I could fit a desktop motherboard inside the chassis, which let me to discover motherboard form factors. I knew if I was going to go the distance of buying my own motherboard, I would want to be able to put in my own CPU, so that narrowed the list down to only Mini ITX motherboards, as smaller ones don't have CPU sockets. After some hunting, I found what looked like the perfect motherboard: a Gigabyte GA-IMB310TN. It was advertised as "Thin Mini ITX", meaning that it was physically thinner than other Mini ITX boards. Specifically, it didn't have any tall I/O on the back, and had horizontal RAM trays and a shorter PCIe socket. After a few days of considering my options, I decided I wanted to go with the Gigabyte motherboard, and try to build a PC from scratch. This meant that I could let myself think of this project as building an actual daily-driver laptop, not just a gee-whiz computer. With that in mind, I set out to find parts for the motherboard.

Because of the size constraint, I needed to find components that were not only small, but cool. Finding RAM and an SSD were easy, but the CPU and GPU were harder decisions to make. The motherboard has an Intel 1151 socket, which thinned my options to 7th and 8th gen Intel CPUs. I quickly aquainted myself with Intel's CPU naming conventions and went off to search for a low-TDP CPU. Intel's discrete consumer CPUs typically have a TDP of 65w, whereas their integrated laptop CPUs usually have TDPs between 15w and 30w. Thankfully, Intel made a few low power discrete CPUs. After some hunting, I found an Intel Core i5 8600T that I liked, with a 35w TDP. Good enough.

I haven't actually bought a GPU yet, but I've nearly decided on a Nvidia GTX 1650 Low Profile discrete graphics card. It's just small enough to fit beside the motherboard in the case and still have room for wiring, as long as I take off the bracket and the fans. (Don't worry, I'll leave the heatsink and put in my own fans.) The only other good option is a Radeon RX 560 Low Profile, which is a little bit harder to find, a little bit less expensive, an AMD card (It'll work better in a hackintosh), and a lot less powerful.

Put it (almost) all together, and you get this:
The motherboard with the CPU, RAM, SSD, and some random WiFi card I had lying around installed. Looks pretty cute.

Finding the Right Display

The stock display in the old PowerBook is a piece of junk today, but in 1994 it was absolutely glorious for a laptop computer. At a full 480p and (in some configurations) 16-bit color, all in a thin 1cm flatscreen package, it was easily the best screen to grace a laptop in history. As cool as it would have been to reuse that monstrosity, its ribbon cables were far from standard. After some uneventful Newegg and Ebay trawling, I remembered something. I rummaged around in my closet and came out with the display panel from a 2nd gen iPad whose case did not fare as well as the screen. The iPad ran its last clock cycle as it sailed through the air after my littlest brother angrily chucked it following and unfortunate game of Ninja Fruit. The screen persevered. To my surprise, the screen perfectly fit the hole where the old screen was, backlight and all. Not only that, but putting such a small screen (it's about 3mm thick) in such a thick screen case left over a centimeter of empty room behind it. Perhaps a triple monitor laptop is simply as easy as buying two more iPad screens and fitting them to slide out each side! I still had to find a way to interface with Apple's proprietary display plug, but Ebay had several converters to choose from.

Finding the Right Battery

This was a very daunting task for a couple reasons. For one, the battery in this laptop must be beefy enough to comfortably power every component inside it under full load without exploding. Because I chose low power components, I estimated the absolute peak power draw to be about 175 watts. I found some drone batteries that had some pretty crazy discharge rates, but that led me to the other problem: the battery life has to actually be decent if I want to seriously use this computer. Even at an idle, I estimated that a pair of 50C 5000mAh batteries would barely last an hour. Not good.

It was in this time of strife that I stumbled upon a heavenly battery, the legendary Li-Ion 18650 cell. That's a cylindrical cell that is 18mm in diameter and 65mm long and with spectacular battery life for its size. It's so good it literally has a subreddit dedicated to it. Another attractive part about this particular cell was its modularity. Wiring doesn't cost much space, so I can essentially pack a cell in every available spot I can find. There's even a few places in the monstrous screen that will fit an 18650 or two. I forsee managing to fit a 3s5p or even 3s6p configuration in the chassis. The majority of the batteries will be in the palm rest.

To charge all these batteries and fulfill the power requirements of the motherboard, I bought a 24v 6A power supply off amazon, which should be enough to charge the thing. I may end up buying a legit desktop power supply if I ever want to run it under heavy load.

Finding the Right Cooling Solution

Finding a way to cool desktop parts in a laptop frame is the hardest, the most fun, and the wildest engineering gauntlet I'm facing. I'm not accustomed to worrying about temperatures, so this took some research. I did some R&D myself just by taking apart an old Dell Latitude I had to see how it was cooled. I found some peculiar copper pipes that seemed to route heat to a heatsink, which I later found out were hollow heat pipes, something I didn't even know existed.

The Dell with the keyboard off. The heat pipes are clearly visible.

The inside of the Dell.

I discovered that one can buy unshaped heat pipes off Ebay or wherever for about $10 a tube, which looked like a great option: find a way to pipe the heat to heatsink on the side of the case, then find a way to push air out the heatsink. It's also bound to look cool. Within that one idea, there's actually dozens of equally bad ways to put fans on the thing. I'll break down every option I considered.

One big ol' fan... somewhere: I would really like to use a purpose-built case fan if I can, so the first thing I looked at was a low profile case fan. I found a 92mm x 14mm Noctua fan on Amazon that I considered mounting on a sheet of plexiglass beneath the keyboard, and making the keyboard somehow rise a little bit when the computer's open so the fan has air to suck from. This design wouldn't directly route air from the fan to the heatsink, it would require capping exits from the case besides the heatsinks such that air must escape through them. Lifting the keyboard to let air get in is kinda hacky, though.

A bunch of little fans: Noctua also makes these cute little 40mm x 10mm fans that looked like a great idea, except that I can't really think of places to put them. I could easily put them in the palm rest, but that means I can't use it as a palm rest because I'd block the air.

A centrifugal fan: This would be the best option, if somebody made fans that were a size I liked. With a centrifugal fan, I could route the air directly into a heatsink without needing to worry about making the case airtight. I could also perhaps set a fan on the bottom of the case near the side, and build a wall in the case such that air comes in the side, down into the fan, out the fan into the case, then out the heatsink. Doing that would probably mean sacrificing battery space, however. I wish there was a good way to use the large empty space above the motherboard.

A cross flow fan: I actually found out about these cool little things today while searching Digikey for fans. A cross flow fan has a similar effect to a centrifugal fan, except on a different axis. They're long and skinny and push a lot of air. I've thought about finding a way to have intake grills on the front of the case, and have air flow into the case form the from with a pair of these fans flanking the trackpad.

Water cooling!: Of course I had to look at what it would take to water cool this system. Sadly, water cooling systems are just way too big, especially radiators.

Where I Am Now

I have a computer that boots, an empty PowerBook case, a crying wallet, and a lot of ideas. No cooling or working screen or batteries yet. I have actually successfully booted MacOS on a junker netbook I had, so I know I can do that now. I'm at the stage where I need to decide if this is really possible or not. I'm measuring before I cut. Any ideas?
This is an awesome project, and I'm excited to see where it goes (and a bit envious that you have the time to pursue such fun projects). I have no particular ideas to offer, especially seeing how much thought you've already put into the project and how much you've succeeded at solving major problems (e.g., how do you get sufficient performance to drive three high-density displays in a DIY laptop?). I'm glad you stumbled on the 18650 yourself: reading that paragraph, I was going to suggest that battery, and in fact, for a while many laptop batteries were just collections of those tossed into a shell! Are you going to use the original keyboard and touchpad, and if so, have you determined if they're PS/2 and can be cajoled into working via USB-to-PS2 adapters? Or if not, what keyboard/touchpad might you put in?

Please keep us posted with frequent updates, and don't hesitate to bounce questions where we might have experience or insight off us here!
KermMartian wrote:
This is an awesome project, and I'm excited to see where it goes (and a bit envious that you have the time to pursue such fun projects).

Why, thank you!
KermMartian wrote:
Are you going to use the original keyboard and touchpad, and if so, have you determined if they're PS/2 and can be cajoled into working via USB-to-PS2 adapters? Or if not, what keyboard/touchpad might you put in?

You have just successfully read my mind. As you typed that up I was already busy at work designing a new PCB to replace the one in the current old keyboard. The stock keyboard had good travel and action even by today's standards, and it fits the computer perfectly because it's stock. I would interface with the keyboard directly, but its only connections are two ribbon cables leading to two flexible keyboard matrix PCBs, the mapping of which is pretty unconventional. No electronics anywhere. I thought this was a good opportunity to try some hardcore prototyping and make a replacement PCB and solder on a USB HID controller chip, so the keyboard can operate with very little extra wiring. This is the keyboard controller I plan on using. Here's some pics of the original keyboard:
Front of the keyboard.
Back of the keyboard. Notice the rubber contacts for each key in the round holes.
The PCBs sitting on the keyboard's frame. Taking the darn thing apart required sawing plastic rivets off that frame, which was a pain! Each ribbon cable connects to a different PCB.
My work so far on the keyboard PCB. Because of how small the rubber domes are, I'm measuring by tenths of millimeters.

Oh, and did I mention RGB? O_o
KermMartian wrote:
Are you going to use the original keyboard and touchpad, and if so, have you determined if they're PS/2 and can be cajoled into working via USB-to-PS2 adapters? Or if not, what keyboard/touchpad might you put in?

I think it's likely that these are ADB (Apple Desktop Bus - basically Apple's ps/2). It's pretty easy to convert ADB to USB with a teensy and TMK firmware. I'm sure there's other options out there, but that's what I'm using as I type this.

I've been messing with some li-ion batteries lately - you definitely want to be careful when charging them. Getting them much over their nominal max-charge voltage (usually 4.1-4.3v) can damage them and cause fires. Even if the average cell voltage is in the right range, the cells will tend to unbalance over time - the weakest cells will get weaker, and eventually could become overcharged and potentially explode.

This is definitely a cool project, and I'd like to see more from it. Hack on!
35W is still a lot of power to dissipate through a laptop-sized heatsink- you're probably going to need a lot of airflow since there probably isn't much vertical clearance for any kind of heatsink (and thus not a lot of available heatsink surface area).

Fabricating a thermal module based on heatpipes is going to be either very difficult or very expensive. I'd think a decent solution that doesn't require specialized tooling would involve taking a sufficiently low-profile heatsink and removing the base material except where it would contact the CPU lid. Then you can push air across it however (and probably across the GPU as well). Starting with an aluminum or copper extrusion wouldn't be too difficult to work with hand tools.

Thinking about this more though (and not having any numbers on the available height you have to work with), I think an off-the-shelf 1U cooling solution (for 1-rack-unit servers) might do fine and be both easier and no more expensive than a custom solution. For instance, Thermaltake's Engine 27 heatsink is a very attractive piece of metal:


As a desktop (rather than server) platform the LGA1151 socket doesn't have a lot of 1U options (though it may be compatible with some server sockets; I haven't looked into it), so off-the-shelf options may be relatively few. But if there's an off-the-shelf option with sufficiently low profile that seems like the best choice.
There's quite a few laptops with CPUs that big - I know my thinkpad t500 can run a 35W dual-core CPU, but a 50W quad-core is pushing it. That might be because the heat sink is only designed for a single die, and the quad-core has two, one of which doesn't have great thermal contact with the heat pipes. I've also owned a 17-inch HP that used a desktop 3.06Ghz P4 - not a particularly cool CPU. It had a TDP of 81.8W and two fans

You might be able to repurpose the CPU cooler+fan module from a laptop - you might need to fabricate a mechanical adapter, but it sounds like you're capable of that
Hooloovoo wrote:
I've been messing with some li-ion batteries lately - you definitely want to be careful when charging them. Getting them much over their nominal max-charge voltage (usually 4.1-4.3v) can damage them and cause fires. Even if the average cell voltage is in the right range, the cells will tend to unbalance over time - the weakest cells will get weaker, and eventually could become overcharged and potentially explode.

This is definitely an issue I've been keeping in mind, but I wasn't aware of increased imbalance over time like that. Is it enough to just put an overcharge protection circuit on every individual cell, or should I find a way to put in a true balance charger? With the latter, how would I arrange the cells on the charger? This is a large enough array of batteries that I don't think it makes sense to balance each cell individually. Perhaps balance by series?
Tari wrote:
35W is still a lot of power to dissipate through a laptop-sized heatsink- you're probably going to need a lot of airflow since there probably isn't much vertical clearance for any kind of heatsink (and thus not a lot of available heatsink surface area).

While you're right, I'm actually quite happy with the space I've allotted to a heatsink. The heatsink will occupy the entire vertical space to the left of the motherboard in this picture:

And yes, I finally fit the motherboard in the case! I had to cut a few things, but I was careful to leave the pillars integral to the computer's structure.
Case: dremeled.
Tari wrote:
Fabricating a thermal module based on heatpipes is going to be either very difficult or very expensive.

What makes you say this? I've found several places where I can buy 10" pipes for $10 a pipe, and I'm confident I can shape them without kinking.
Tari wrote:
Thinking about this more though (and not having any numbers on the available height you have to work with), I think an off-the-shelf 1U cooling solution (for 1-rack-unit servers) might do fine and be both easier and no more expensive than a custom solution. For instance, Thermaltake's Engine 27 heatsink is a very attractive piece of metal:

It looks great, but sadly, it's just too tall. From the top of the CPU lid to the bottom of the keyboard, I have 13-14mm of clearance. Enough for some things, not enough for a mounted CPU cooler.
Hooloovoo wrote:
You might be able to repurpose the CPU cooler+fan module from a laptop - you might need to fabricate a mechanical adapter, but it sounds like you're capable of that

In one of my earlier posts there's a picture of a laptop heatpipe+heatsink assembly I took out, which actually helped me keep the CPU at a reasonable temp while in BIOS. I would have used the fan in that laptop too, but I fried it with a 150W power supply a couple days out of idiocy. However, Amazon/Digikey has a respectable assortment of laptop fans, which I'll probably end up using for their space-saving advantages.

In other news, I've gotten around to routing my PCB after learning all about nets and vias and pads and whatnot. The autorouter in the program I'm using is very poor, so I'm routing them all by hand. Here's what a button looks like:


Also, I discovered that the gold coating inside the case is quite conductive. What sort of shield should I have between the case and the motherboard? I'm definitely going to mount the motherboard slightly above the case floor, but I'm fearing that flex would cause a short on the bottom of the board.
A security sponge would be the best protection between the case and the board.

Also Kapton Tape.
Kapton tape indeed - or perhaps there is something you can spray/paint it with to alleviate the problem?
  
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