GA-586ATV & ECS P5VX-Be:Fixing CPU Table for AMD K6-2

by cp » Mon Apr 03, 2006 3:15 pm

Hello!
Lately i've been messing around with some old socket7 stuff. This time i got my hands on a Gigabyte GA-586ATV and an ECS P5VX-Be 2.0, flashed the patched BIOS, modded the voltage regulators for 2.2v, replaced some caps and installed AMD K6-2 400. Both machines work fine, except for the speed display and therefor the cpu initialization. The GA-586ATV gets it completely wrong recognizing a 80486-DX2 66MHz and the ECS P5VX-Be detects an AMD K6-2/256. It would be nice if someone could fix the cpu tables for both boards maybe adding correct initialization values, too.
Thanks for your help!

BiosMan · by **KachiWachi** » Tue Apr 04, 2006 2:30 pm

Contact Jan Steunebrink.

http://web.inter.nl.net/hcc/J.Steunebrink/k6plus.htm

by **Denniss** » Wed Apr 05, 2006 12:50 pm

The P5VX-Be with Bios 1.5 should perfectly support any K6-2 but may not show the correct MHz number.

The GA-586ATV may need to be patched by the http://www.rom.by Bios patcher

by cp » Wed Apr 05, 2006 6:09 pm

wrote an email to jan a few days ago. though no reply yet.
patched the GA-586ATV bios with BiosPatcher already, seems to work :) cpu gets recognized correctly. no info on the write allocation bits yet. maybe i'll check later.
and yes...the P5VX-Be supports and recognizes the K6-2. the correct MHz number just would be a cosmetic change.
so..case closed i guess ;)

BiosMan · by **KachiWachi** » Thu Apr 06, 2006 1:19 pm

You can use Jan's DOS utility to dump the CPU MSR's and check their status.

Everest can also do this from Windows.

You can then use a third-party application such as WAMonitor to setup the CPU to your liking.

by **edi** » Mon Jul 24, 2006 5:49 am

cp wrote:Hello!
Lately i've been messing around with some old socket7 stuff. This time i got my hands on a Gigabyte GA-586ATV and an ECS P5VX-Be 2.0, flashed the patched BIOS, "modded the voltage regulators for 2.2v, replaced some caps" and installed AMD K6-2 400. Both machines work fine, except for the speed display and therefor the cpu initialization. The GA-586ATV gets it completely wrong recognizing a 80486-DX2 66MHz and the ECS P5VX-Be detects an AMD K6-2/256. It would be nice if someone could fix the cpu tables for both boards maybe adding correct initialization values, too.
Thanks for your help!

HI to all

....I want to know what are the "modded the voltage regulators for 2.2v, replaced some caps" that you speak here..

I have a GA-586ATV and I want to put a k6-2 350 Mhz...
Is that for this MOBO...??
What set(modded) for 2.2V?
What caps replace??

I don't flash the Patched Bios ( from www.rom.by) still but...now i have a Pentium MMX166 working in this MOBO. with a Bios 1.28.

Thanks in advance.

edi :lol:

by cp » Mon Jul 24, 2006 10:38 am

Jan already patched the Gigabyte GA-586ATS bios for AMD K6-2/3(+), Cyrix 433 and IDE upto 128GB support. Thank you again for your great work Jan!

The modding of the (linear) voltage regulator is done by adding another resistor to the board which changes the output voltage from 2.8V to ~2.2V. This is very cheap mod and it has some disadvantages: The efficiency of linear regulators isn't very good. They get quite hot as they just 'burn' the voltage that is not needed. To the extent the regulator on the GA-586ATS is limited to 8.5A, a K6-2 350 needs 9.85A (worst case), so good cooling is needed. The caps were just replaced with larger ones (larger in capacity) to meet the need of higher current by the AMD K6-2.

One could build a switching regulator and replace the linear regualtor, but that would be way too expensive and complicated.
I'll post some pictures and information on how to mod the linear regulator to output 2.2V thus driving an AMD K6-2 and on how to apply additional cooling.

by **edi** » Tue Jul 25, 2006 11:18 pm

OK thanks to you cp..
I wait for the post with pictures an info...about this..
two questions,,,,,

1º Were is the patched bios from Jan that you talk..? ¿Is diferent from that we can get from use the Bios Patcher program from www.rom.by ???

2º You talk about GA-586ATS .... I have the GA-586ATV....is...this a problem....or not?

Bets regards

edi

by cp » Wed Jul 26, 2006 9:23 am

1.) the bios Jan provided is still in beta testing stage and not released yet. it's very different from the result biospatcher provides.

2.) my mistake..i was talking about the GA-586ATV but typed GA-586ATS. to state it again: i have a GA-586ATV modded and the bios patched by Jan is for the GA-586ATV, too. sorry for the confusion.

by cp » Wed Jul 26, 2006 6:00 pm

1.) set JP6 & JP7 to 1-2 (both). that's the setting for 3.3V VCore, we won't need it anymore.
2.) locate the regulator. it's an AS2880. you'll find it right next to the cpu socket mounted on a small heatsink
3.) locate R27
4.) take a resistor, value 220 Ohm (red-red-brown or SMD: 221) and solder it parallel to R27
5.) make sure to apply additional cooling on the regulator (larger heatsink and/or large (eg. 80mm) fan on the cpu and regulator).
6.) before plugging in a cpu check your work at least twice

closeup
jumper settings and additional information

by **edi** » Fri Jul 28, 2006 8:17 am

Hello
Take a look to this:

This ( ok sorry bad picture)....was take from the MOBO.

This is the Regulator a settings zone from my MOBO..aka GA-586ATV rev. 4b
The MOSFET is a RFN45N03L ...and the "mini Chip" a Rayteon..RC5041 switching regulator that control the REG(this can probably provide a Setup to down the voltage to 2.2V).
The dipswitch (6 vias) setup Bus Clock, Multiplier and Vcore...for 2.9 or 3.2V(this last for AMD K6).

Is clear that your MB is not the same.!!
I think that is not posible to make the MOD that you show with this MOBO..but
my question is Any sugestion about this??

Best regards

edi

by cp » Fri Jul 28, 2006 10:04 am

lucky you! but only on first sight. your mainboard has a switching regulator (4bit, VCore downto 2.1V) which is way more efficient than a linear regulator. no need to apply some special cooling to the regulator. the sad thing is: they have a cpu voltage autodetection based on some cpu pin(s). the best thing would be to bend up VID0-3 of the RC5041 and disconnect the cpu autodetection (my guess: an extra resistor to the feedback pin). or modify the 2.9V VCore setting to output 2.2V with some resistors. but either would need some indepth research, reverse engineering of the circuit and some measuring on the board itself. i don't own such a board..sorry.

by **KenH** » Fri Jul 06, 2007 4:35 am

cp wrote:Jan already patched the Gigabyte GA-586ATS bios for AMD K6-2/3(+), Cyrix 433 and IDE upto 128GB support. Thank you again for your great work Jan!

I was led here by searching for a bios for this same board, mines Rev4B,
& was hoping to find a bios to run a K6 cpu as well, this board I have
here has up to 5.5 miltiplication on it, & figured it may be possible with the
right bios...
Is anyone here willing to share the bios patched by Jan...
Thanks...

BiosMan · by **KachiWachi** » Fri Jul 06, 2007 2:00 pm

Jan's Website -

http://web.inter.nl.net/hcc/J.Steunebrink/k6plus.htm

by **KenH** » Fri Jul 06, 2007 6:09 pm

KachiWachi wrote:Jan's Website -

http://web.inter.nl.net/hcc/J.Steunebrink/k6plus.htm

I hit that page & a few others 1st but to no avail...
Am I missing something..?