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questions about running an athlon xp-m barton (AXMA2800FKT4C) on a via kt133a board (iwill kk266+) or dead cpu?

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First post, by stanwebber

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i was hoping this would just work out of the box (at least crippled), but alas no post.

this is a desktop replacement barton mobile cpu with a 133mhz fsb (16x muliplier) running at 1.65v stock. the cpu it is replacing is a palomino xp with a 133mhz fsb (13x multiplier) running at 1.75v stock, but can be over/undervolted a full 0.1v on this board. looks like a good match? no?

i'm using an iwill kt266+ which is one of the last kt133a boards released. the official bios supports up to a palomino xp 2100+, but i have flashed it (permanent, no fallback option) with the rom.by patcher that adds the cpu microcode of the later athlons:

https://www.vogonsdrivers.com/getfile.php?fil … 904&menustate=0

the bios setup allows for up to a 15x multiplier, but the 16x mobile barton is unlocked? right? it should be happy at a lower multiplier or am i mistaken that all xp-m bartons are multiplier unlocked?

i've tried all the tricks trying to get this cpu to post from removing everything except 1 stick of ram to jumpering 100mhz fsb and of course clearing the cmos in between, but no post. of course there's always the possibility the cpu is doa, but i've been around a lot of dead athlons back in the day and this cpu has a perfect core and not a hint of discoloration from thermal abuse. even the dead athlons with no chips always had some physical indicator something was amiss. i've checked for missing pins too, all of them (recently had an athlon 1400 thunderbird with no bent pins, but oddly missing 2 random pins from the middle).

was i wrong-headed in thinking this would just work? do i need to pin-mod? or is it not even possible to get this combo working? will an xp-m with a lower multiplier work? any advice from someone with this board or a later revision abit kt7a (or any kt133a board) would be welcome. thanks.

Reply 1 of 3, by stanwebber

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i've been doing a lot of reading of old forum posts from back in the day and the problem may stem from the fact that the barton xp-m i'm using has a multiplier higher than 12.5x. even though my motherboard has bios options for 13, 14 and 15x, it's doubtful that the 5th bit (8) of the cpu l3 bridge is being read since amd didn't implement it until post palomino--well after the last bios update for the board was released . supposedly the 13, 14 and 15x multipliers are remapped for late 1.3, 1.4ghz thunderbirds corresponding to 12.5, 5, and 5.5x.

i though maybe if i pin modded the l3 bridge to pull the 5th bit (8) low it would force the multiplier down from 16x to 8x which would put it in the lower range of the motherboard, but the board still won't post. did this even have a chance of working? i read that palominos use a combination of l3, l4 and l10 (mapped via 5th bit on l1) bridges to determine a multiplier up to 18x whereas the thoroughbred/barton variants add a 5th bit (8) to the l3 bridge and use that solely. (my xp-m barton has all the l4 bridges cut and no l10 bridge.) how does the bios know about this?

i guess i don't comprehend what the rom.by update to the cpu microcode entails. i thought all the mechanics of recognizing the cpu would be included in 'adding support for later athlon xp cpus'; otherwise, why even bother?

Reply 2 of 3, by mockingbird

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If you ever do get something later than Palomino working on it, I'd love to know. It's my only KT133A board that won't work with Barton.

For every other board, I do this to the bottom side of the board on the socket:

The attachment cpu.png is no longer available

I think iWill has some kind of lockout routine, but who knows.

mslrlv.png
(Decommissioned:)
7ivtic.png

Reply 3 of 3, by stanwebber

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this is the simple pin mod i used. i was under the impression that it pulled the 5th bit of the l3 bridge low, but the more i read about this stuff, the more i am confused. my l3 bridge is :--:: which doesn't even seem to match up with a 16x multiplier.

The attachment pinmod.jpg is no longer available

in my research i found a couple of posts from people attempting the same with this iwill board that are very discouraging:

Re: Two dead "retro rocket" mobos?

Re: Iwill KK266+ (KT133A) with Mobile Athlon 4

i 'm beginning to think this will never be possible unless someone hacks the bios specifically for it.

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