Reverse Engineering A Classic ThinkPad Battery

The ThinkPad 701 is an iconic laptop series from the mid-90s and is still highly sought after today because of its famous butterfly keybaord. The laptop itself is tiny even by the standards of the time, so in order to fit a full-size keyboard IBM devised a mechanism where the keyboard splits and slides over itself to hide away as the screen is closed. But, like most 30-year-old laptops, the original batteries for these computers are well past their prime. [polymatt] takes us through all of the steps needed in order to recreate a battery from this era down to the last detail.

He starts by disassembling an old battery with extensive damage from the old, leaky batteries. The first part of the recreation is to measure the battery casing so a new one can be modeled and printed. The control boards for the batteries of these computers were not too sophisticated, so [polymatt] is able to use a logic analyzer with a working unit to duplicate its behavior on an ATtiny microcontroller. With that out of the way, a new PCB is created to host the cloned chip and a new battery pack, made out of 9 NiMH cells is put together.

[polymatt] wanted this build to be as authentic as possible, so he even goes as far as replicating the label on the underside of the battery. With everything put together he has a faithful recreation of this decades-old battery for a famous retro laptop. ThinkPads are popular laptops in general, too, due to their fairly high build quality (at least for their enterprise lineups) and comprehensive driver support especially for Linux and other open-source software projects like coreboot and libreboot.

Thanks to [Roman UA] for the tip!

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The ThinkPad You All Wish You Had, With A Brain That’s Not Ancient

An IBM (or, later, Lenovo) ThinkPad is a popular choice in our community. They’re prized for their rugged design, longevity, and good software support. Over the many years that the line has been available, there have been a few models which have captured the attention more than others, and among those, probably the most sought-after is the ThinkPad 701c. It would be an unremarkable mid-1990s 486 laptop were it not for the party piece of that flip-out butterfly keyboard (see video, below). [Karl Buchka] has one that’s profoundly dead, and rather than use it as a novelty paperweight, he’s giving it a new lease of life with a Framework motherboard.

This is very much a work in progress, so there will be plenty more to come, but so far, he’s taken the display panel from an iPad and made it work with the Framework board, and designed an entirely new lower case for the Thinkpad. This will hold the Framework board with its USB-C ports at the edge, so in the place of its USB-based expansion modules, he’s made a custom external port replicator. Meanwhile, a Teensy handles that unique keyboard. We’re told that the design files will all eventually be put online should anyone else want to try.

We’d normally be slightly upset were someone to butcher something as unusual as a 701c, however, in thic ase we can see that it turns a broken computer into one that should see quite a bit of use.  We can’t help envying him this project.

Understandably not many 701c owners have dived inside their machines, but we have previously brought you a contemporary processor upgrade. If you’ve never seen the 701c’s keyboard — or you just want to see it again — here you go:

Thanks [Ł. Juszczak] for the tip.

Getting The Most From Fading ThinkPads

The ThinkPad line of laptops has been widely prized not only by businesses but also by those who appreciate a high standard of hardware quality and repairability. But some think the cracks are starting to form in their reputation, as it seems that new ThinkPads are sacrificing quality for aesthetics and cost. As a result a huge modding scene has popped up around models that are a few years old like [Cal] found out when working on this X230.

At first he only made some cosmetic improvements to the laptop like replacing the worn palm rest, but quickly found himself in a rabbit hole with other upgrades like swapping out the keyboard and battery. The new keyboard is a 7-row X220 keyboard, which required modification of the connector and flashing the embedded controller with a hacked image to change the keyboard map without needing to make changes at the OS level. From there, he decided to replace the lackluster screen with a 1920×1080 matte IPS panel using an adapter board from Nitrocaster, and finished off his upgrades with a customized Coreboot BIOS for improved performance and security.

While Coreboot doesn’t remove all of the binary blobs that a bootloader like libreboot does, the latter is not compatible with more modern machines like this X230. Still, you’ll get many benefits from using Coreboot instead of the stock bootloader. For running Linux on a daily driver laptop, we appreciate all of these updates and expect that [Cal] will get plenty of years of use out of his machine. We’ve definitely seen an active modding scene for ThinkPads that were (at the time) seven years old and still going strong, so we’d expect nothing less for this one.

That Old ThinkPad Needs An Open Source 2.5″ IDE SSD

So you fancy yourself a FOSS devotee, do you? Running GNU/Linux on your old ThinkPad, avoiding devices that need binary blobs? Got LibreBoot installed too? Not bad, not bad. But what about the hard drive? Can you be sure you aren’t leaking some freedoms out of that spinning rust?

Well, worry no more. Thanks to the work of [dosdude1], we now have an open source solid state drive that’s designed to work with any device which originally used a 2.5 inch IDE hard drive. The choice of releasing it under the GPL v3 versus an open hardware license might seem an odd choice at first, but turns out that’s actually what the GNU project recommends currently for circuit designs.

Fair warning: all the chips on the board are BGA.

Which is precisely what we’re talking about here — just a circuit design done up in KiCad. There’s no firmware required, and the PCB features very little beyond the four BGA152/BGA132 NAND flash chips and the SM2236 controller IC. You’ve just got to get the board fabricated, obtain (or salvage) the chips, and suddenly your retro laptop is sporting the latest in mass storage technology.

So how does it work? The SM2236 is actually a CompactFlash (CF) controller, and since IDE and CF interfaces are so similar, the PCB doesn’t have to do much to adapt from one to the other. Sprinkle in a few NANDs, and you’ve got yourself a native SSD suitable for old school machines. [dosdude1] says the board can slot four 64 GB chips, which should be more than enough given the age of the systems this gadget will likely be installed in. There are a few catches though: the NAND chips need to be supported by the SM2236, and they all have to match.

If you need something even smaller, [dosdude1] produced a 1.8 inch SSD using the same techniques back in October of last year.

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A T700 laptop motherboard with its parts labelled

Replacement Motherboard Brings New Lease Of Life To Classic Thinkpads

“They don’t make them like they used to.” It might be a cliché, it might not even be entirely true, but there’s something special about owning a piece of hardware that was built to a much higher standard than most of its contemporaries, whether it’s that bulletproof Benz from 1992 or that odd fridge from 1987 that just seems to last forever. For laptop aficionados, the Thinkpad series from IBM and Lenovo is the ne plus ultra: beloved for their sturdy construction and rich feature set, they have been used anywhere from the United Nations to the International Space Station. The T60 and T61 (introduced in 2006) are especially famous, being the last generation sporting IBM logos and such classic features as 4:3 displays and infrared ports.

The thing is, even the best hardware eventually becomes obsolete when it can no longer run modern software: with a 2.0 GHz Core Duo and 3 GB of RAM you can still browse the web and do word processing today, but you can forget about 4K video or a 64-bit OS. Luckily, there’s hope for those who are just not ready to part with their trusty Thinkpads: [Xue Yao] has designed a replacement motherboard that fits the T60/T61 range, bringing them firmly into the present day. The T700 motherboard is currently in its prototype phase, with series production expected to start in early 2022, funded through a crowdfunding campaign.

Designing a motherboard for a modern CPU is no mean feat, and making it fit an existing laptop, with all the odd shapes and less-than-standard connections, is even more impressive. The T700 has an Intel Core i7 CPU with four cores running at 2.8 GHz, while two RAM slots allow for up to 64 GB of DDR4-3200 memory. There are modern USB-A and USB-C ports as well as well as a 6 Gbps SATA interface and two m.2 slots for your SSDs.

As for the display, the T700 motherboard will happily connect to the original screens built into the T60/T61, or to any of a range of aftermarket LED based replacements. A Thunderbolt connector is available, but only operates in USB-C mode due to firmware issues; according to the project page, full support for Thunderbolt 4 is expected once the open-source coreboot firmware has been ported to the T700 platform.

We love projects like this that extend the useful life of classic computers to keep them running way past their expected service life. But impressive though this is, it’s not the first time someone has made a replacement motherboard for the Thinkpad line; we covered a project from the nb51 forum back in 2018, which formed the basis for today’s project. We’ve seen lots of other useful Thinkpad hacks over the years, from replacing the display to revitalizing the batteries. Thanks to [René] for the tip.

USB-C Charging On Your ThinkPad, One Step At A Time

Hackers love their ThinkPads. They’re easy to work on, well documented, and offer plenty of potential for upgrades. For the more daring, there’s also a wide array of community-developed modifications available. For example, [Berry Berry Sneaky] has recently put together a step-by-step guide on swapping the common ThinkPad rectangular charging port (also used on ThinkBooks and other Lenovo machines) for USB-C Power Delivery.

Now to be clear, this is not a new concept. But between freely sharing the STL for the 3D printed adapter, providing a full parts list, and providing clear instructions on how to put it all together, [Berry Berry Sneaky] has done a fantastic job of making this particular modification as approachable as possible. For the cost of a common PDC004 Power Delivery “trigger” module and a bit of PETG filament, you can add yet another device to the list of things that work with your shiny new USB-C charger.

While not strictly necessary, [Berry Berry Sneaky] recommends getting yourself a replacement DC input cable for your particular machine before you crack open the case. That will let you assemble everything ahead of time, making the installation a lot quicker. It will also let you keep the original rectangular power jack intact so you can swap it back in if something goes wrong or you decide this whole unified charging thing isn’t quite what you hoped for.

Not a member of the ThinkPad Army? No worries. We’ve seen a lot of interest in using these configurable USB-C trigger modules to upgrade all manner of devices to the new Power Delivery standard or sometimes put together custom battery chargers for their older mobile gadgets.

Building An Open Source ThinkPad Battery

If you own a laptop that’s got a few years on the clock, you’ve probably contemplated getting a replacement battery for it. Which means you also know how much legitimate OEM packs cost compared to the shady eBay clones. You can often get two or three of the knock-offs for the same price as a single real battery, but they never last as long as the originals. If they even work properly at all.

Which is why [Alexander Parent] decided to take the road less traveled and scratch built a custom battery for his ThinkPad T420. By reverse engineering how the battery pack communicated with the computer, he reasoned he would be able to come up with an open source firmware that worked at least as well as what the the third party ones are running. Which from the sounds of it, wasn’t a very high bar. From a more practical standpoint, it also meant he’d be able to create a higher capacity battery pack than what was commercially available should he chose to.

A logic analyzer wired in between one of the third party batteries and a spare T420 motherboard allowed [Alexander] to capture all the SMBus chatter between the two. From there he wrote some Arduino code that would mimic a battery as a proof of concept. He was slowed down a bit by an undocumented CRC check, but in the end he was able to come up with a fairly mature firmware that even allows you to provide a custom vendor name and model number for your pack.

The code was shifted over to an ATtiny85, with a voltage divider wired up to one of the pins so it can read the pack voltage. [Alexander] says his firmware still doesn’t do a great job of reporting the actual battery capacity remaining, but it’s close enough for his purposes. He came up with a simple PCB design to hold the MCU and support components, which eventually he plans on putting inside of a 3D printed case that actually plugs into the back of his T420.

This project is obviously still in a relatively early stage, but we’re very interested to see [Alexander] take it all the way. The ThinkPad has long been the hacker’s favorite laptop, and we can think of no machine more worthy of a fully open hardware and software battery pack.