The Russians over at OverClockers.ru have found some interesting details about the AMD Applebreds. They have found another soldering mod, to turn an AMD Applebred Duron into an Athlon XP :
There is hardly a point to transform a $45 Duron processor into a $60 Athlon XP one, but, on the other hand, such modification is very interesting from theoretical point of view. We remember that AMD Athlon XP “Thorton” processors are set to appear in the market pretty soon, given that Thorton core is an altered Barton core and has only 256KB of L2 in contrast to Barton’s 512KB of L2, we assume that there will be a way to transform Thorton into Barton winning a massive gain in performance. Hence, the Duron is only the beginning!
If you take a closer look on AMD Duron and AMD Athlon XP processors you will notice only tiny difference: an L2 bridge is not locked on the Duron processor. If you lock it again, everything should work and the processor will have an L2 cache of 256KB!
Believe it or not, but, at least, some of AMD Duron microprocessors functioned very well with re-soldered L2 and functional 256KB of L2 cache! Unfortunately, not all Duron CPUs may work absolutely correctly with 256KB of L2, and the report tells us about a Duron processor with enabled 256KB of L2 that crashed system again and again until the guys switched the L2 off in BIOS. Another Duron chip worked absolutely stable with 256KB of L2 even when overclocked, thus, there is a lottery with Duron processors with functional 256KB L2 at this point.
More information can be found at X-bit Labs