After years of seeing people showing off and trading their badge Simple Add-Ons (SAOs) at Supercon, this year I finally decided to make one myself. Now for a first attempt, it would have been enough to come up with some cool PCB art and stick a few LEDs on it. But naturally I started with a concept that was far more ambitious than necessary, and before long, had convinced myself that the only way to do the thing justice was to have an onboard microcontroller.
My first thought was to go with the venerable ATtiny85, and since I already had a considerable stock of the classic eight-pin DIP MCUs on hand, that’s what I started prototyping with. After I had something working on the breadboard, the plan was to switch over to the SOIC-8 version of the chip which would be far more appropriate for something as small as an SAO.
Unfortunately, that’s where things got tricky. I quickly found that none of the major players actually had the SMD version of the chip in stock. Both DigiKey and Mouser said they didn’t expect to get more in until early 2024, and while Arrow briefly showed around 3,000 on hand, they were all gone by the time I checked back. But that was only half the problem — even if they had them, $1.50 a piece seems a hell of a lot of money for an 8-bit MCU with 8K of flash in 2023.
The whole thing was made all the more frustrating by the pile of DIP8 ATtiny85s sitting on the bench, mocking me. Under normal circumstances, using them in an SAO wouldn’t really be a problem, but eight hand-soldered leads popping through the front artwork would screw up the look I had in mind.
While brooding over the situation my eyes happened to fall on one of the chips I had been fiddling with, it’s legs badly bent from repeated trips through the programmer. Suddenly it occurred to me that maybe there was a way to use the parts I already had…
Continue reading “Chip Shortage Engineering: Misusing DIP Packages”
Why did [Hales] end up hacking the BIOS on a 10 year old laptop left over from an Australian education program? When your BIOS starts telling you you’re not allowed to use a particular type of hardware, you don’t have much of a choice.
Originally [Hales] planned on purchasing a used Lenovo X260 to replace his dying laptop, but his plans were wrecked. A pandemic-induced surge in demand that even the used laptop market caused prices to bloat. The need for a small and affordable laptop with a built in Ethernet port led to the purchase of a Lenovo Thinkpad x131e. Although the laptop was older than he liked, [Hales] was determined to make it work. Little did he know the right-to-repair journey he was about to embark on.
Problems first arose when the Broadcom WiFi adapter stopped working reliably. He replaced it, but the coaxial antenna cable was found to be damaged. Even after replacing the damaged cabling, the WiFi adapter was still operating very poorly. Recalling past problems with fickle Broadcom WiFi adapters, it was decided that an Intel mPCIe WiFi adapter would take its place. When power was re-applied, [Hales] was shocked to find the following message:
Unauthorized network card is plugged in – Power off and remove the miniPCI network card
And this is where things got interesting. With off the shelf SOIC8 clips and a CH340 programmer, [Hales] dumped the BIOS from the laptop’s flash chip to another computer and started hacking away. After countless hours of researching, prodding, hacking, and reverse engineering, the laptop was useful once again with the new Intel WiFi adapter. His site documents in great detail how he was able to reverse engineer the BIOS over the course of several days.
But that’s not all! [Hales] was also able to modify the hardware so that his slightly more modern mPCIe WiFi adapter would come back on after the computer had been put in Hibernation. It’s an elegant hack, and be sure to check [Hales’] site to get the full details. And at the end, there’s a nice Easter egg for anybody who’s ever wanted to make their laptop boot up with their own logo.
We applaud [Hales] for his fine efforts to keep working equipment out of the landfill. We’ve covered many hacks that had similar goals in the past. Do you have a hack you’d like to share? Submit it via the Tips Line.