oachalon was able to send me his 7426 BIOS. It appears to be the same as the 7422 BIOS on fizi's site. As he reports on his site, people have found the BIOS does work on the eMachine laptops, but with the battery meter problem. I tried the 7426 BIOS myself, and because I have the older motherboard which takes the 0F08 BIOS and not the NS BIOS, I have the battery meter problem, and also the onboard Ethernet is not detected correctly - I could not force it to work with the driver. But it DID BOOT INTO WINDOWS WITH THE TURION!

So what this means is that those with a 7422 and 7426 should be able to upgrade to a Turion without any problems. I'm one step away from modding the eMachines BIOS to have it work with the Turion. I modded it enough so that it passes the POST and boots Windows up to the point where the mouse pointer appears. Then it freezes. Probably there's one setting that I've missed in the BIOS, so I'm combing through it now. I'll keep you posted!