I may have changed my mind about buying a Framework Laptop 13 this year, but I’m not done being excited about the company’s products. Heck, I’m more enthusiastic than ever — because it looks like Framework is seriously planning to let us snap a second removable battery into a laptop.

One week ago today, the modular laptop company announced a 16-inch notebook that promises to let you swap out its entire butt for one that fits a discrete graphics chip, extra fans, or a pair of SSDs — and / or swap out the Framework Laptop 16’s entire keyboard deck to add, say, a numpad or fancy LEDs or virtual piano keys. It promised more details later this year.

But Framework didn’t actually stop at that tease: it also published design specifications on its GitHub for everyone to see. Here’s what I learned from digging through it.

If you want a graphics card you can slide right into the back of a laptop — power, data, the works — you might want a lot of pins. As you’re about to see, the Framework Laptop 16’s Expansion Bay has 148 contacts between the laptop’s motherboard and the daughterboard you’ll find in each module. And Framework has already revealed what they do.

On GitHub, Framework shares the entire pinout, and I’d like to draw your attention to No. 41 and No. 63: the first “allows power to be fed from the Expansion Bay back into the laptop in an Extended Battery scenario,” while the second can “control 2nd battery discharge,” among other things. Oh, and pin No. 62 is specifically labeled an “I/O pin for 2nd battery.”

While the pinout also suggests that the Framework Laptop 16 may be able to use the same pathways to charge itself over a USB-C PD port built into an Expansion Bay module, it sure sounds like the company thinks you’ll be able to use two batteries with this laptop.

Speaking of USB-C PD power, another part of the pinout suggests Framework anticipates this laptop might go beyond 100W charging someday. Pin No. 39 “will be high when connected to the PD power source >=180W,” the company reveals.

Plus, pin No. 1 states that “while on AC with a high power adapter, Vsys will be 20V, with maximum current up to 10.5A,” which means Framework’s anticipating a power adapter as big as 210W could plug into this machine — though it’s possible those modules could use a barrel jack for power rather than a 240W USB-C PD 2.1 cable.

You might also be happy to hear there’s dedicated PWM speed control for two independent cooling fans — so you should theoretically be able to tune the noise level of an expansion module — and a pin that can be monitored “to put GPU in min power state.” Like many laptops, maybe you’ll be able to save battery by switching to integrated graphics even with the discrete GPU attached.

The pinout also confirms how much bandwidth to expect from Expansion Bay modules. In case you missed it in the CEO’s blog post, you get eight lanes of PCI-Express for your GPU and SSDs. It’s not the 16 lanes you’d get from a desktop, but it’s better than the PCIe x4 that held back early external GPUs.

It didn’t quite hit me until I watched the Linus Tech Tips video, but the entire deck of this laptop is Input Module City. It’s a huge canvas. Here’s a screenshot from Linus’ video because (as an investor in the company) he’s the only one Framework has shown it to so far:

On GitHub, the company explains that you can build three different types of modules, all of which use the same row of springy contacts you see in the middle.

Keyboard-sized modules (283.16mm wide)

Numpad-sized modules (67.85mm wide)

Half-sized modules (33.825mm wide)

They’re each limited to 3.7mm tall and roughly 114.35mm deep and can draw up to 500mA of 5V power and 100mA of 3.3V power. The system can tell them when the computer’s asleep and keep them minimally powered, just like how a normal laptop touchpad and keyboard are waiting for your tap to wake the machine again.

The modules don’t need to be powered, by the way! At Framework’s event last week, I saw little strips of wood, metal, plastic, and even marble that can be slotted next to your keyboard or touchpad to make your machine look unique.

But Framework has also created a few powered example modules for those who want the juice, each running on a Raspberry Pi RP2040 chip. And Linus got to touch one that we didn’t get to try last week: an incredibly low-power secondary screen.

Framework’s calling this prototype module the B1 Display, and it’s a 4.2-inch, 300 x 400-pixel black-and-white screen, which sounds a little ho-hum at first — except this panel has no backlight and is designed to refresh just a single time per second (or optionally up to 32fps) for ultra-low power. Think original PalmPilot or Game Boy.

It can display your animated GIFs, flip into an inverted-color dark mode, and defaults to a screensaver, in part because “the current panel is susceptible to image retention,” Framework writes.

Looking for something a little smaller or brighter? Check out Framework’s LED Matrix. The company’s GitHub reveals that it’s got nine columns and 34 rows for 306 LEDs in all, supports both greyscale and black-and-white images, and can already play animated patterns, scroll content vertically, display a clock, or even play some very basic games.

Here’s just a moment of Pong:

It can also run Tetris, Snake, and even a working copy of Conway’s Game of Life, according to the documentation. Yes, you could theoretically have multiple Turing-complete simulations running right alongside your keyboard as you type.

When the laptop goes to sleep, it’s programmed to slowly transition the LEDs to off. Here’s the back of the prototype LED Matrix module so you can see how it’s all laid out:

Mind you, it’s not clear how many modules Framework will build itself or which it might actually decide to sell. The 40-person company hasn’t historically thrown its money into every possibility and hasn’t released all that many modules yet itself. The reason it publicly released the documentation and revealed the Framework Laptop 16 early is because it doesn’t want to go it alone. It wants everyone — from big companies to individual hackers — to build cool new parts for this ecosystem.

The Framework Laptop 16 is the coolest computing concept I’ve seen in years, so I really hope it works out. We’ll bring you the full official specs, price, and more later this year.