Kudzu: Re: pot on V1.
Short answer is "I dunno" - pots don't really have "positive, GND and other" pins.
My V1 hack uses only two pins of the pot. I have a variable resistance between 0 and 50K between those pins. The other resistor is still a 100K to GND.
Basically - look at my "100K and 27K pot" picture, then mentally substitute "2 pins of a 50K pot" in place of the 27K pot to get my adjustable mod. The easiest way of figuring out which pins to use for your particular pot is to have an ohmmeter sitting on two pins while you tweak the pot.
For your V3, I recommend the original Turbo3 hack, available in the ~100-message thread on "sw2... sw3... what's the right setting?"
http://www.linux-hacker.net/cgi-bin/UltraBoard/UltraBoard.pl?Action=ShowPost&Board=technical&Post=1528&Idle=0&Sort=0&Order=Descend&Page=0&Session=
Turbo3 has pictures of his V3 hack at:
http://photos.yahoo.com/bc/turbo3pictures
In a nutshell, Turbo3's hack puts the resistor divider network entirely on U16.
You can see the differences in board layouts near U16 by looking at my V1 (tackhead_1999) and Turbo's V3 (turbo3pictures) pics on our Yahoo briefcases.
R342 and R343 do not exist on a V1, so I had to go the other route (building the resistor divider network on the SMT cap near the power supply) suggested by Las_Vegas in this thread:
http://www.linux-hacker.net/cgi-bin/UltraBoard/UltraBoard.pl?Action=ShowPost&Board=technical&Post=1624&Idle=0&Sort=0&Order=Descend&Page=0&Session=
Las_Vegas has a pic of his V1 hack here:
http://www.lvcm.com/lna/images/vcoreadj.jpg
The only thing he's done differently is he got his GND from the other end of C248, and I got my GND from the other end of C257.
For lifting the pad of U16, nail polish should do the trick, with the caveat that it'll be difficult to remove. I went for hot glue, which, given the delicate nature of U16, will probably be impossible to remove without breaking the pin.
As I see it, the risk isn't that the pin will "drop" down onto the pad, but that something (like the wire you send to the pin!) will eventually wiggle or strain or break the pin off. Holding it in place so that it can't move is probably the better way to protect against damage. But the better you hold it in place, the less-reversible the mod will be.
('Course, once you've got K6-III in a WinChip-based unit, as long as you keep the speed low enough for Q16 to run cool, you'll never *want* to go back!)
