millobo2016 wrote on 2025-01-17, 13:11:

PCB thickness is 0.062 inches, 2oz thick copper inner layer, four-layer board design

All good.

millobo2016 wrote on 2025-01-17, 13:11:

1. Chip resistor 0805 56 ohm (front, back)

These are resistor arrays, also known as resistor packs. 4 resistors in 1 package. The package size is often referred to as 0804 or 0805 (same thing).
Can be 56, 65 or 75 Ohm.

millobo2016 wrote on 2025-01-17, 13:11:

2. Tantalum capacitor D case 6.3V 470uf (front)

Can also be C, D or E case. 470 uF is good, but 100, 220 or 330 uF would be also fine.

millobo2016 wrote on 2025-01-17, 13:11:

3. Chip resistor 0805 150 ohm 1% x3 (front R1-R3)
4. Ceramic capacitor 0603 1uf (front, back)

All good.

millobo2016 wrote on 2025-01-17, 13:11:

5. Ceramic capacitor 1206 0.1uf (one on the back)

Can be 0805. MUST be 0.1 uF. Can be type X5R or X7R.
No need for 1206.

In addition, I have made jumper pins at positions jp1, jp2, and jp3.

If you only intend to use Pentium Pro at default clock speeds and only one CPU, you can just solder the jumpers with wire to their "Normal" position.

I would also like to ask, can I leave the positions of these three chip resistors on the front blank?
Or should I solder 56 ohm chip resistors at these three locations?

All 0804 56 ohm resistor arrays MUST be soldered. CPU won't start without them.

I choose 0603 1uf ceramic capacitors to solder in these positions. Is this specification OK? I also choose 0603 ceramic capacitors of the same specification on the back. Is there any problem with this?

All good. It is designed for 0603. Capacitance can be 0.1 uF - 1 uF.
1 uF is better.

I find this location very strange, with only one 0805 or 1206 0.1uf ceramic capacitor? What is this capacitor used for, and why only 0.1uf specifications are used?

This capacitor is used for decoupling internal PLL (clock generator/multiplicator) of the CPU. It must be 0.1 uF type X5R or better (X7R or C0G), according to Intel Pentium Pro documentaion.

so I would like to ask for the detailed bill of materials (BOM) of S8S1_FINAL

I don't have any, really. This is all you need to make it work:
Socket 8 (x1)
SMD Resistor Array 0804 56 Ohm (x38)
SMD Ceramic Capacitor 0603 (x46)
SMD Resistor 150 Ohm 1% 0806 (x3)
SMD Ceramic Capacitor 0.1 uF 0805 X7R (x1)
SMD Tantalum Capacitor, case size C, D or E. Can be 100uF - 470uF. (x11)
All capacitors must be 6.3V or higher.

I spent more than $1000 on this.

That's... fascinating.

Please try and post all your questions in a single post.
Also, since you found my live stream with me building the adapter, just do everything as I do.

You might want to read the schematic for the 440bx in my sig.
I know it's different, but it's very similar.

Most of the 56ohm resistors feed power to the signals. Vtt.

The capacitors are mostly decoupling capacitors. They reduce noise.

Anyway, the schematic should make it clearer what the likely purpose of the components on the adapter are for.

How is this project going? Has there been updated and uploaded project to a pcb manufacture? I would love to get a few made for my dual slot boards. I get dual slot boards often here from ewaste place i go to so i could test them in several boards to help development if anything. I also purchased few nos sockets to build this as well.

I've been on other things, but the files are attached if someone with more knowledge wants to continue it.

Mentat-vvo wrote on 2025-01-09, 14:31:

arti9m wrote on 2025-01-09, 12:18:

Sorry, missed that initially. You're wrong here again, I already booted both max1024 BIOS . it means your CPUs are also not synced properly (just like with my adapters) and they will NOT work in a multiprocessor OS. Possibly due to FSB being too high.

My CPUs are right )) they have right BIOS by mentat-vvo. But the Asus P2B-D has many tweaks to do with soldering to operate properly. My board does not install WinXP in ACPI mode with dual Piii-coppers. MPS mode, however, worked for me. I’d try kmeow’s new bios btw if he had corrected those issues I’ve addressed. It seems he did not.

Ps. Freeway mobo is on its way to receive patched bios.

I am drooling over this build.

Very nice.

Looks like modern reproduction adapters?

P2B-D (and XG-DLS also) have hardware bug that breaks ACPI under XP/2K: https://arstechnica.com/civis/threads/asus-p2 … -xp-pro.838874/

There

Mentat-vvo wrote on 2025-01-09, 14:31:

arti9m wrote on 2025-01-09, 12:18:

Sorry, missed that initially. You're wrong here again, I already booted both max1024 BIOS . it means your CPUs are also not synced properly (just like with my adapters) and they will NOT work in a multiprocessor OS. Possibly due to FSB being too high.

My CPUs are right )) they have right BIOS by mentat-vvo. But the Asus P2B-D has many tweaks to do with soldering to operate properly. My board does not install WinXP in ACPI mode with dual Piii-coppers. MPS mode, however, worked for me. I’d try kmeow’s new bios btw if he had corrected those issues I’ve addressed. It seems he did not.

Ps. Freeway mobo is on its way to receive patched bios.

I assemble one PCB from arti9m, now I'm just missing the resistor networks.
I found one with proper size on Mouser: https://cz.mouser.com/ProductDetail/Bourns/CA … DNIFyNlig%3D%3D
(I have to wait until I'll do some bigger odrer now...)

Sphere478 wrote on 2025-01-30, 03:57:

I am drooling over this build.

Very nice.

Looks like modern reproduction adapters?

Yes

Paadam wrote on 2025-01-30, 17:36:

P2B-D (and XG-DLS also) have hardware bug that breaks ACPI under XP/2K: https://arstechnica.com/civis/threads/asus-p2 … -xp-pro.838874/

I'd say it breaks ACPI completely, but as far as I know it still should've booted, but the CPU load will be 50% or more.
Anyways, I believe it is fixable:
https://web.archive.org/web/20010208235838/ht … i/solution.html

arti9m wrote on 2025-01-31, 21:18:

I'd say it breaks ACPI completely, but as far as I know it still should've booted, but the CPU load will be 50% or more. Anyways […]
Show full quote

Paadam wrote on 2025-01-30, 17:36:

P2B-D (and XG-DLS also) have hardware bug that breaks ACPI under XP/2K: https://arstechnica.com/civis/threads/asus-p2 … -xp-pro.838874/

I'd say it breaks ACPI completely, but as far as I know it still should've booted, but the CPU load will be 50% or more.
Anyways, I believe it is fixable:
https://web.archive.org/web/20010208235838/ht … i/solution.html

For what it's worth, that fix worked perfectly on my P2B-DS

Is there a post where I can download and try out the gerber files? I want to order couple pcbs to try out, I have some server boards here with the odd chipset to see if it will work.

I also see mentat's posting one as well, not sure whos who has the right ones to test with and confused by all this

arti9m wrote on 2025-01-11, 05:19:

I have a few questions for the community regarding upcoming revision 2 of the adapter. […]
Show full quote

I have a few questions for the community regarding upcoming revision 2 of the adapter.

1. Do you need jumpers for selection between 66/100/133 MHz bus frequency? Do you need physical jumpers or SMD 0-ohm resistors would be fine? Or dipswitches, perhaps?
2. Do you need jumpers for voltage selection (upto 3.5V, but PPro itself runs at 3.3V anyways)? Can those be SMD 0-ohm parts?
3. Do you need physical jumpers for the BR1/BR3 hack to be able to choose between Dual 440BX board and any other dual board, or SMD jumpers would suffice?
4. If you have Pentium Pro 1M and/or Pentium 2 Overdrive, could you please test if certain pins are shorted with a multimeter? I'd provide a photo of which pins to test.
5. Do any of you plan to use Dual PPro setup on a motherboard that can do Data Bus ECC? Does anyone even have a Slot-1 mobo capable of that?
6. Do any of you plan to do any kind of JTAG debugging?

I'm trying to omit as much unnecessary stuff as possible to make the design simpler.

Tyan Thunder 2500 in the flesh.
With a couple of evil P!!!s awaits Pentium Pros.

Oh that motherboard is on my list... 8gb of ram? Yes please.

I wonder if PAE works on ppro chips?

Datbluehusky wrote on 2025-02-04, 20:49:

Is there a post where I can download and try out the gerber files? I want to order couple pcbs to try out, I have some server boards here with the odd chipset to see if it will work.

I posted mine a few pages ago: Re: Dual Pentium Pro Build Thread
But please be patient and wait until someone makes a version that actually works in a dual CPU setup. And with faster clock speeds.

Mentat's boards are not opensource and no gerbers of those exist in public.

@Mentat-vvo @luckybob
Please be careful when populating those server boards with lots of big RAM sticks. I had already 3 server boards repaired with fried buffer chips between the chipset and RAM slots. All chips on those RAM sticks often have shared CAS/RAS lines. RAM sticks themselves have buffers but only for CAS I think. RAS buffering is up to the motherboard, and it's a HUGE current load. Some boards actually mention in their user manual NOT to install sticks with too many chips.

What about single cpu mode? is there a stable version that can do 200mhz?

arti9m wrote on 2025-02-05, 11:51:

I posted mine a few pages ago: Re: Dual Pentium Pro Build Thread But please be patient and wait until someone makes a version th […]
Show full quote

Datbluehusky wrote on 2025-02-04, 20:49:

Is there a post where I can download and try out the gerber files? I want to order couple pcbs to try out, I have some server boards here with the odd chipset to see if it will work.

I posted mine a few pages ago: Re: Dual Pentium Pro Build Thread
But please be patient and wait until someone makes a version that actually works in a dual CPU setup. And with faster clock speeds.

Mentat's boards are not opensource and no gerbers of those exist in public.

@Mentat-vvo @luckybob
Please be careful when populating those server boards with lots of big RAM sticks. I had already 3 server boards repaired with fried buffer chips between the chipset and RAM slots. All chips on those RAM sticks often have shared CAS/RAS lines. RAM sticks themselves have buffers but only for CAS I think. RAS buffering is up to the motherboard, and it's a HUGE current load. Some boards actually mention in their user manual NOT to install sticks with too many chips.

Datbluehusky wrote on 2025-02-04, 20:49:

Is there a post where I can download and try out the gerber files? I want to order couple pcbs to try out, I have some server boards here with the odd chipset to see if it will work.

I also see mentat's posting one as well, not sure whos who has the right ones to test with and confused by all this

arti9m wrote on 2025-01-11, 05:19:

I have a few questions for the community regarding upcoming revision 2 of the adapter. […]
Show full quote

I have a few questions for the community regarding upcoming revision 2 of the adapter.

1. Do you need jumpers for selection between 66/100/133 MHz bus frequency? Do you need physical jumpers or SMD 0-ohm resistors would be fine? Or dipswitches, perhaps?
2. Do you need jumpers for voltage selection (upto 3.5V, but PPro itself runs at 3.3V anyways)? Can those be SMD 0-ohm parts?
3. Do you need physical jumpers for the BR1/BR3 hack to be able to choose between Dual 440BX board and any other dual board, or SMD jumpers would suffice?
4. If you have Pentium Pro 1M and/or Pentium 2 Overdrive, could you please test if certain pins are shorted with a multimeter? I'd provide a photo of which pins to test.
5. Do any of you plan to use Dual PPro setup on a motherboard that can do Data Bus ECC? Does anyone even have a Slot-1 mobo capable of that?
6. Do any of you plan to do any kind of JTAG debugging?

I'm trying to omit as much unnecessary stuff as possible to make the design simpler.

Re: Dual Pentium Pro Build Thread
Kicad. Go for it.

arti9m wrote on 2025-02-05, 11:51:

@Mentat-vvo @luckybob
Please be careful when populating those server boards with lots of big RAM sticks. I had already 3 server boards repaired with fried buffer chips between the chipset and RAM slots. All chips on those RAM sticks often have shared CAS/RAS lines. RAM sticks themselves have buffers but only for CAS I think. RAS buffering is up to the motherboard, and it's a HUGE current load. Some boards actually mention in their user manual NOT to install sticks with too many chips.

When the buffer chip dies the board won't display any POST codes too on the port 80 card? I have P3TDE6 that suddenly just died. Turns on and off nicely from power button but no codes and no POST. RESET signal on permanently.

Datbluehusky wrote on 2025-02-06, 00:40:

What about single cpu mode? is there a stable version that can do 200mhz?

Yeah the one I linked can do 233MHz (66x3.5). It can do even more, It is just limited to 83MHz FSB.
But the desired FSB for many is 100MHz, which it cannot do. And the ultimate goal is 133MHz FSB.

But keep in mind that I didn't do any long-running stability tests yet. I did boot into OS, played Duke3D and Doom for a bit and it was fine.
I will get back to the project in a week or two and post updates soon.

Paadam wrote on 2025-02-06, 06:45:

When the buffer chip dies the board won't display any POST codes too on the port 80 card? I have P3TDE6 that suddenly just died. Turns on and off nicely from power button but no codes and no POST. RESET signal on permanently.

It did display codes. The behavior was the same as the memory sticks weren't installed. One of the boards died gradually, not detecting some memory at first and then not detecting memory at all.
But your board doesn't even have the buffer chips. It is much newer, uses SD-RAM sticks which have less chips, thus consuming less current. The issue probably lies somewhere else.

Using the open source design provided by Arti9m, a first replica was finally produced in Taiwan. Today is 2025/03/08

Thoughts (personal opinion only)
Advantages
1. Open source design, any enthusiast can have it
2. Simple design, five components plus a socket8 slot can operate
3. Can run super pi 32M and games without problems
4. CPU placed horizontally, beautiful appearance
Disadvantages
1. Slightly poor compatibility, P3B-F Mod bios can operate, P2L97 1.02 bios lacks microcode and cannot install XP, Tekram P6F40K-A5 cannot boot
2. No overclocking performance, FSB I can only use 66Mhz or 75Mhz, CPU operating speed is 233Mhz or 225Mhz
3. The original author Arti9m said that dual CPUs cannot operate

I forgot to mention one advantage, which I personally am very satisfied with, that is, the design of Arti9m is fully compatible with the bracket used by Socket 370, even if the bulky original pentium pro cooler is installed, it is absolutely safe and stable