UPDATE:- UNLOCKING THOROUGHBRED 2200+ OR JUST A WORKAROUND??
Many 13.5X Tbred 2200+ systems refused to boot, or mobo/bios were unable to reset the Multiplier to lower settings for oc'g with Host Clock higher than 133Mhz, even though L1 bridges interfacing to the mobo were closed.
Then xtremesystems.org discovered that closing the 3 open L3 bridges enabled systems to not only boot at 11X, but also enabled mobo/bios to reset Multipliers from 5X thru 12.5X, (range where only the lower 4 Bit Values are reset).
Pcstats.com had also solved a similar 13X Palomino 2100+ problem by hard modding Multiplier bridges to 10.5X, which reset its new 5th 8X default HI Bit Value to LO, from L10 = open/closed to closed/open. So the new L10 bridge pair was interpreted as an "unlocking switch". Closing Tbred 2200's 3 individual open L3 bridges, which also resets its 8X Bit Value from HI to LO by closing its rightmost L3 bridge, is also being called the way to "unlock" its Multiplier.
But unlocking the Multiplier has meant closing open interfacing L1 bridges which then allows mobo/bios to reset all Multiplier Bit Value settings, while modifying the Palomino's L10 and Tbred's L3 Multiplier bridges actually resets the 8X Bit Value from default HI to LO, and the 8X Bit Value is probably still locked, but LO.
So the popular interpretations are misleading, the L10 bridge pair and L3 bridges mods are workarounds for mobo/bios unable to reset only the 8X Bit Value from default HI to LO. Problem may have begun when 4 bit Duron/Tbird Multiplier code changed to 5 bit Palomino code, some legacy mobo/bios with 4 interfacing circuits obviously unable to reset the 5th 8X Bit Value. Others may not yet have bios with updated CPU ID info or translation Tables for Multipliers higher than 12.5X, we may never know all the reasons. The mod discoveries are noteworthy and work, but understanding the true nature of the problem suggests other workarounds to enable similar 5X thru 12.5X mobo/bios control of the Multiplier.
Fill and close only the rightmost 8X L3 bridge. Or connect a single wire from Socket A pin AJ27 to a 100 ohm resistor screw grounded to external case, as in PCB Multiplier mod above. Either should be easier than filling and closing 3 L3 bridges. System should boot at 5.5X with the same 5X thru 12.5X mobo/bios control as the 3 bridge mod booting at 11X.
Update 6/30/02:- Deerhunter's Thread at xtremesystems.org reported closing only the rightmost 8X Bit Value L3 bridge with a conductive trace around its cut, no insulating fill, then booting to 5.5X with Multiplier control from 5X thru 12.5X available from bios, but 13X and higher not working.
Supports issue of problems between some mobo/bios and 8X Bit Value circuit, and validates the single 8X L3 bridge Tbred 2200+ workaround. Also supports single wire mod
