GoKawiilAMD Athlon and Duron CPUs famously unlocked via the pencil trick
In the late 1990s and early 2000s, AMD's Athlon and Duron processors, especially those based on the Thunderbird core, could be unlocked for overclocking by reconnecting the L1 bridges with graphite from a pencil. This method allowed users to bypass factory lockouts and increase CPU speeds beyond standard settings, making these chips popular among enthusiasts. The hack was a response to AMD's initial use of laser-cut locks to prevent overclocking and became a symbol of DIY hardware tuning.