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K6-2/3+ Success on Asus P5A 1.06 - simple mod

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Reply 60 of 112, by Sphere478

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https://www.mouser.com/ProductDetail/Bourns/C … DtrMHoVsA%3D%3D

This is probably the one or similar to the one I used

Update:
Mod is unstable

3dmark 2k runs 40fps in first test with mod but then crashes after a test or two

With jumper removed it runs at 20fps but stable

Could try the pull down setting I suppose?

981 marks 3dmark 2k

K6 3+ 550 at 550
Radeon 9800 pro at stock clocks windows xp sp3 driver
windows kp sp3
Ssd
Sata

Just had a successful benchmark run,
Reinstalled jumper without booting in pull up position

Running benchmark again no other changes not even reboot.

It worked for a little but then blank screen

Tried pull down, yet again unstable.

Only stable setting is no jumper

Last edited by Sphere478 on 2021-12-27, 06:15. Edited 1 time in total.

Sphere's PCB projects.
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Sphere’s socket 5/7 cpu collection.
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SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod
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Tyan S1564S to S1564D single to dual processor conversion (also s1563 and s1562)

Reply 61 of 112, by Sphere478

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Any ideas?

Is my use of the alternate vcc3 pin the issue? (Do not they all go to the same place?)

Last edited by Sphere478 on 2022-03-31, 21:36. Edited 1 time in total.

Sphere's PCB projects.
-
Sphere’s socket 5/7 cpu collection.
-
SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod
-
Tyan S1564S to S1564D single to dual processor conversion (also s1563 and s1562)

Reply 62 of 112, by snufkin

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Vcc3 should all be 3.3V for handling I/O.

It's interesting that it's unstable both with pull up and pull down. The WB/WT# pin should be a toggle between Write Back (when pulled high) and Write Through (pulled low) cacheing policies. The original mod suggests that the board is stuck in WT mode, so pulling it high forced it in to WB mode. Pulling it low should just put it in WT mode, which is what it was in anyway, so it's odd that it causes instability. Maybe the chipset is sometimes trying to change between the two modes and fails.

Things I'd check:
board off and disconnected, remove the jumper, then check resistance between each pin on the jumper header and GND and 3.3V on the ATX power connector (so 6 readings in total). That should confirm what's connected to what, and if there was an existing pull up/down on the WB pin.
Also, with the board on and the jumper off, measure the voltage from the middle pin on the jumper (should be the WB pin) and GND. If it stays at 0V then the CPU is in write through, if it sometimes blips then something is occasionally switching it to write back.

Maybe (and I'll be surprised) using the CPU power pins is causing a problem and those two wires should go direct to the ATX 3.3V and GND.

Reply 63 of 112, by IcySon55

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Thanks for the mouser link. I think I've finally narrowed it down to what I wanted to get: https://www.mouser.ca/c/passive-components/re … tance=1%20kOhms

The CPUs I have on hand to test my 1.06 board with are the K6-2+ 550ACZ and the K6-2 550AGR. Next up, all of the soldering stuff.

Reply 64 of 112, by Sphere478

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I’m seeing instability it seems even with the jumper removed.

I think I need to try removing the mod entirely.

Problem is I glued the wires down 🤣. Crap

Sphere's PCB projects.
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Sphere’s socket 5/7 cpu collection.
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SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod
-
Tyan S1564S to S1564D single to dual processor conversion (also s1563 and s1562)

Reply 65 of 112, by Sphere478

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Update: no matter what I try this board refuses to be stable.

I don’t believe it had anything to do with the mod as I inspected connections and checked them with volt meter and microscope before giving board power

But in hindsight something I could have maybe tried was putting the jumper within the cpu socket area to minimize emi.

Sphere's PCB projects.
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Sphere’s socket 5/7 cpu collection.
-
SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod
-
Tyan S1564S to S1564D single to dual processor conversion (also s1563 and s1562)

Reply 66 of 112, by snufkin

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Where you able to get the wires unglued and removed? Was the board 100% stable before the mod? If you can get it back to being stable, then maybe putting a small 0.1uF capacitor between the WB pin and the nearest GND pins would help deal with any noise that the wires are possibly picking up? Also, I think the mod should work (if it works) having just the WB wire connected to the CPU. The 3.3V and GND could come directly from the ATX connector, so there'd be no chance of injecting any noise in to the CPU power pins.

Reply 67 of 112, by Sphere478

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snufkin wrote on 2021-12-20, 15:44:

Where you able to get the wires unglued and removed? Was the board 100% stable before the mod? If you can get it back to being stable, then maybe putting a small 0.1uF capacitor between the WB pin and the nearest GND pins would help deal with any noise that the wires are possibly picking up? Also, I think the mod should work (if it works) having just the WB wire connected to the CPU. The 3.3V and GND could come directly from the ATX connector, so there'd be no chance of injecting any noise in to the CPU power pins.

Since I knew the mod was required I did not do any tests prior

Turns out that those glued wires are pretty permanent. 🙁

1.04 version of the board will be here soon no more issues. 😀

Sphere's PCB projects.
-
Sphere’s socket 5/7 cpu collection.
-
SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod
-
Tyan S1564S to S1564D single to dual processor conversion (also s1563 and s1562)

Reply 68 of 112, by Sphere478

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Guys I think I may have messed up, I think my stability issues may have been the 9800 pro that I was using 🤣

I actually managed to scrape off all the super glue using heat and a brass wire brush and remove the mod but am now doing it all over again haha

This time inside the socket area to avoid any EMI risk

Last edited by Sphere478 on 2021-12-27, 21:31. Edited 1 time in total.

Sphere's PCB projects.
-
Sphere’s socket 5/7 cpu collection.
-
SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod
-
Tyan S1564S to S1564D single to dual processor conversion (also s1563 and s1562)

Reply 69 of 112, by Sphere478

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I give you mod v 3.0!

Note glue over resistor for stability and glue under jumper

Last edited by Sphere478 on 2021-12-29, 03:46. Edited 2 times in total.

Sphere's PCB projects.
-
Sphere’s socket 5/7 cpu collection.
-
SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod
-
Tyan S1564S to S1564D single to dual processor conversion (also s1563 and s1562)

Reply 70 of 112, by lukas12p

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Good to hear that You found what was the problem. I would recommend to use GF3 or slower cards 😀
What is that third wire for in Your picture? And why do You need option to disable "+++" mod?

Reply 71 of 112, by Sphere478

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lukas12p wrote on 2021-12-27, 10:34:

Good to hear that You found what was the problem. I would recommend to use GF3 or slower cards 😀
What is that third wire for in Your picture? And why do You need option to disable "+++" mod?

The mod is setting a option in how the cpu uses wb/wt (write back/write through) to set this option you pull it high, or pull it low.

The faster option is pulling it high (OP mod), and how the jumper is set in the pic.

But should I ever wish for it I also have the option to force it low. Or disable the mod entirely. In which case the motherboard will do what it does or rather doesn’t do well because of the defect.

Some users have reported the mod doesn’t like other cpus. So for when I play around with other cpus I can disable the mod or force it high or low for them also.

Sphere's PCB projects.
-
Sphere’s socket 5/7 cpu collection.
-
SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod
-
Tyan S1564S to S1564D single to dual processor conversion (also s1563 and s1562)

Reply 72 of 112, by IcySon55

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Looking at your V3 mod, it makes me wonder if there is anywhere on the board where we could mount a front-facing set of jumpers and manually label them as the wb/wt options. Transparent stickers with white ink for a silk-screen mod anyone?

Just a fun thought. 😄

Reply 73 of 112, by Sphere478

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IcySon55 wrote on 2021-12-30, 06:21:

Looking at your V3 mod, it makes me wonder if there is anywhere on the board where we could mount a front-facing set of jumpers and manually label them as the wb/wt options. Transparent stickers with white ink for a silk-screen mod anyone?

Just a fun thought. 😄

As in drilling holes?

You can see v2.0 of the mod was pretty accessable.

Sphere's PCB projects.
-
Sphere’s socket 5/7 cpu collection.
-
SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod
-
Tyan S1564S to S1564D single to dual processor conversion (also s1563 and s1562)

Reply 74 of 112, by IcySon55

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Either by drilling holes or using some existing holes that won't cause any problems.

Reply 75 of 112, by Sphere478

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IcySon55 wrote on 2021-12-30, 09:14:

Either by drilling holes or using some existing holes that won't cause any problems.

🤔

Best bet is some version of mod 2.0 methinks.

Sphere's PCB projects.
-
Sphere’s socket 5/7 cpu collection.
-
SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod
-
Tyan S1564S to S1564D single to dual processor conversion (also s1563 and s1562)

Reply 76 of 112, by Doornkaat

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The sane solution is a small PCB that does the switching via transistors and can be stuck to the back of the mobo in the middle of the CPU socket. You could connect wires to that to control the transistors without worrying too much about EMI.

Reply 77 of 112, by Sphere478

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Doornkaat wrote on 2021-12-30, 10:44:

The sane solution is a small PCB that does the switching via transistors and can be stuck to the back of the mobo in the middle of the CPU socket. You could connect wires to that to control the transistors without worrying too much about EMI.

I’m able to confirm the mod is working, it like literally doubles the frame rate, the pull down also seems to keep it at half speed not that that is any different than no jumper, but I haven’t played with the board much on other cpus.

But I suspect that v3.0 may be handy for other cpus. At the very least it is nice to have options.

Most people who do this mod I suspect may find use in only a enable/disable jumper. Without pull down option.

Sphere's PCB projects.
-
Sphere’s socket 5/7 cpu collection.
-
SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod
-
Tyan S1564S to S1564D single to dual processor conversion (also s1563 and s1562)

Reply 78 of 112, by Doornkaat

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Sphere478 wrote on 2021-12-30, 10:58:
I’m able to confirm the mod is working, it like literally doubles the frame rate, the pull down also seems to keep it at half sp […]
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Doornkaat wrote on 2021-12-30, 10:44:

The sane solution is a small PCB that does the switching via transistors and can be stuck to the back of the mobo in the middle of the CPU socket. You could connect wires to that to control the transistors without worrying too much about EMI.

I’m able to confirm the mod is working, it like literally doubles the frame rate, the pull down also seems to keep it at half speed not that that is any different than no jumper, but I haven’t played with the board much on other cpus.

But I suspect that v3.0 may be handy for other cpus. At the very least it is nice to have options.

Most people who do this mod I suspect may find use in only a enable/disable jumper. Without pull down option.

I get it.👍 I mean 'sane' in comparison to drilling the board to be able to switch easier.

Reply 79 of 112, by Sphere478

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Coming soon to a motherboard near you.

This device will add a bunch of socket tweaks, including the wt/wb mod and a way to fully disable it if needed.

Socket 5/7/SS7 (Motherboard) Tweaker (Released)

file.php?id=134018&mode=view
file.php?id=133989&mode=view

Last edited by Sphere478 on 2022-03-31, 21:47. Edited 1 time in total.

Sphere's PCB projects.
-
Sphere’s socket 5/7 cpu collection.
-
SUCCESSFUL K6-2+ to K6-3+ Full Cache Enable Mod
-
Tyan S1564S to S1564D single to dual processor conversion (also s1563 and s1562)