Just a bit of praise first for all the hard work you guys have done, you rule!
I have just (somewhat) completed the hack for a k6-3+ cpu.
I did the following: move r60/61 to r184/185. remove r202. pulled up pin 3 of u16. took a wire from pin 3 (isolated from pad) and dropped to ground thru a 100k resistor with a joint using a 50k pot.
I checked the voltage at the now empty r60/61 pads and adjusted the pot to so i got ~1.9 volts or a bit lower.
problems: When i put the CPU in, it came up fine. but the system got hot rather quick. i had a powered fan, but am now using the stock (modified) heatsink. I am only running at 200 mhz (3x66). In the cmos, i checked the cpu temp and system temp. the CPU wasn't very hot, but the system sure was. Also the vcore was reading 2.14V, not the 1.9x i had tried to set it to. I figured it was just too high and dropped it down to 1.7 reading from r60/61 again. this time the Vcore read 2.39 in the cmos!!!!! yanked the plug and instead went to 2.1 V on the pads, reads 1.97 in cmos. finally got it to 1.84 in cmos. Now it seems to run ok. The first time i let it boot. Left it on for a few minutes and it gave me black screen and no response after a few minutes. (this was at the higher voltage mind you, not what it is set to now)
Right now it seems to boot ok. and when it is shut off i CAN turn it back on immediately (couldn't do that with higher volts). Plays Quake 3 pretty dang good. I can beat the computer at hurt me plenty, but my vision gets fishy after a bit from the lousy refresh. Only issue i have is this. CPU temp is now (much) lower than the winchip2 i had. 40C is what it reads now, but system temp is at 60C. If i clock the chip to 266mhz, system temp goes to 76C. But again, i can power the unit back on immediately. so it definately seems close to ok.
PS. about quake3a. yes, i am not joking. It runs q3 decently. i haven't tried the other levels as yet, but will. I am running the video at 400x300 if memory serves (or 320x240) with all settings at absolute minimum. characters and objects look like colored blobs, of course, but it's still pretty dang neat to run q3 on this thing. can't go much higher because of the limited video memory.
pps. just a quick thought for the guys looking to break the 2m video barrier. Is it possible there is a zero ohm resistor acting as a jumper near the trident chip that limits the vid memory, basically ignoring the bios setting? I don't have the pinouts and don't know nearly enough about it to make an informed decision, but that seemed like a possible wrench in the cogs considering all else.