@myne

Not sure if this is the correct datasheet or not, but here.

https://html.alldatasheet.com/html-pdf/257960 … 2/8/F85226.html

myne wrote on 2024-04-20, 12:42:

I... Can't find a datasheet, but this one page blurb claims a pcie to isa bridge chip exists with full isa support except bus master.

Assuming it's accurate, would that imply that lpc isn't needed to support sound cards?

https://www.fintek.com.tw/index.php/products/ … /item/73-f85526

It's been discussed a bit before. Check posts a few pages back. It seems at that time the chip in question wasn't ready yet.

Duffman wrote on 2024-04-20, 13:49:

@myne

Not sure if this is the correct datasheet or not, but here.

https://html.alldatasheet.com/html-pdf/257960 … 2/8/F85226.html

The PCIe-ISA bridge is F85526, which is easily confused with the already known F85226 LPC-ISA bridge chip.

Unfortunately... with new chipsets ditching LDRQ# along with 8237 the PCIe-ISA bridge won't be more useful than F85226 at the moment.

weedeewee wrote on 2024-04-20, 12:59:

I can't help but wonder why […]
Show full quote

myne wrote on 2024-04-20, 12:42:

I... Can't find a datasheet, but this one page blurb claims a pcie to isa bridge chip exists with full isa support except bus master.

Assuming it's accurate, would that imply that lpc isn't needed to support sound cards?

https://www.fintek.com.tw/index.php/products/ … /item/73-f85526

I can't help but wonder why

IS interface supports 8/16bit I/O R/W, memory R/W and DMA R/W (via LPC interface)

is in the description.

edit: sigh, memories Re: MS-98L9 V2.0 , a new 1151MB with an ISA slot

Bugger. Missed that.

I am thinking of getting ISA going on my Gigabyte GA-B85M-D3H that I have, I have managed to find a schematic of it and I know that its other LDRQ signal goes to a 8.2k resistor called NR54 but I have not found any of those magical boardview files. There aren't too many 8.2k resistors and arrays around the PCH but knowing exactly which is the right one would be most helpful...

Tiido wrote on 2024-04-24, 10:29:

would be most helpful...

pm 😉

...and that resistor is located, thänk you very much ~

Now there's a need to sort out the actual bridge business, buy some parts, get a PCB going etc.

myne wrote on 2024-04-24, 11:09:

Tiido wrote on 2024-04-24, 10:29:

Any chance of publicly spilling the beans on where that resistor is located, and which side to connect, so others who might have the same urge & equipment to attach something up to the LPC interface will have a slightly easier time ?
Perhaps a photograph of the main board with a big white X to mark the spot where the treasure is located ?

Let's just say Samuel Morse invented it over 200 years ago and certain documents can be transmitted on it today.

Tiido, this forum holds a hundreds of leaked MB schematics, most of them are for Gigabyte so you're lucky man 😀
https://smd.db-x7.ru/load/skhemy_materinskikh … ma/287-1-0-3134
on my MB the resistor was not populated and I had to put down PCH heatsink to connect a wire on the pad. I hope that UEFI on you MB will not cause extra problems with IRQ/DMA. If you have LPT onboard you can reserve IRQ5/7 for legacy ISA by disabling LPT after boot. I wrote some utility for superIO settings but still not finished, just for my debugging...

red X marks LDRQ on Gigabyte GA-B85M-D3H 1.2

😜 yes, it's just underneath the edge of the heatsink.

myne wrote on 2024-04-24, 11:09:

Thanks !

Tiido wrote on 2024-04-24, 10:29:

Well I destroyed a perfectly good motherboard today, how's everyone else's day going 😁

I can confirm that the Machinist X99-PR9 does NOT have either of its PCH's LDRQ pins wired up anywhere.

I was hoping I could maybe re-use this motherboard as a media center PC in my living room but there's no way I'm getting this PCH back on, especially now I've sanded down the soldermask.

Bit of a shame but at least it wasn't expensive!

(BTW I wrote a utility to pulse the GPIO23 pin at 100hz to look for it on a scope (or speaker, heh). I was able to use it to find other GPIO pins on various resistors but not the magic GPIO23 (for obvious reasons). I'll post the source when I can dig it off the m.2 card that's currently in my machinist motherboard...)

Rasteri, would it be possible to bring it out using a very thin wire after taking off the pch, putting the thin wire in, and putting the pch back on ? 😀

edit: or could it be possible to drill through to the ball from the underside of the board and add a little tiny wire... nevermind that's crazy.

weedeewee wrote on 2024-04-24, 19:45:

Rasteri, would it be possible to bring it out using a very thin wire after taking off the pch, putting the thin wire in, and putting the pch back on ? 😀

edit: or could it be possible to drill through to the ball from the underside of the board and add a little tiny wire... nevermind that's crazy.

To be honest I was thinking about trying to re-attach the PCH using my shitty tools just for fun. I'll try run a wire from the LDRQ pads if I do. I give it a 0.1% chance of success 😁

Drilling might actually be possible if there aren't any other traces in the way. I definitely lack the tools for that though...

rasteri wrote on 2024-04-24, 19:38:

Well I destroyed a perfectly good motherboard today, how's everyone else's day going 😁

Hehe, a science requires sacrifices, good job (x-ray imaging might be better 😀
So it proved that chinese layouter was too lazy to wire it out. Even they didn't fanout all pads to via holes. Drilling through the board may destroy traces in inner layers or cause inter-layer shorts - this is not good idea. Using a very fine enameled wire may work. The wire would need to be fixed on place with some epoxy glue to hold it during PCH soldering. Also it must be fine enough to not suck solder blob outside the PCH ball. Even for me it seems to be a too hardcore soldering job with uncertain result that I would rather avoid, esp. when I can buy some normal old Gigabyte MB that is LDRQ-friendly 😀

GPIO toggle utility - good idea. Would it work for whole PCH family or are the registers specific for each model? Maybe also good to add code in SAPPHISA to check if this pin is configured as LDRQ and configure it so if needed...

I guess one way would be to coat the whole ballpark with some heatresist UV curable coat and then drill out each ballpad down to the copper pad, If you're into that kind of zen meditation(frustration) 😉

Yes, epoxy glue or UV resist would work to shield out sanded solder mask. It prevent melted ball to short each other or be sucked by surrounding copper....
BTW re-soldering of PCH would require some IR radiator for bottom side of MB and hot air for top side, some heat-sensitive components would need to be removed first. As the PCB has many layers it will need a lot heat. Once I tried to replace southbridge on abit BX133 Raid. I think that I did the job properly but the error was probably somewhere elese, later I got another replacement board where I changed damaged DIMM slot...
http://rayer.g6.cz/hardware/abitb133.htm#CHIPSET_REBALL

RayeR wrote on 2024-04-24, 20:16:

GPIO toggle utility - good idea. Would it work for whole PCH family or are the registers specific for each model? Maybe also good to add code in SAPPHISA to check if this pin is configured as LDRQ and configure it so if needed...

I used Whitequark's code as a base (runs under linux) - https://lab.whitequark.org/notes/2017-11-08/a … -ich-pch-gpios/

(EDIT : That is to say, it claims to work on all ICHs and PCHs)

The one good thing about the machinist's BIOS is that pretty much everything is accessible, including stuff like GPIO unlock.

rasteri wrote on 2024-04-24, 19:38:

Well I destroyed a perfectly good motherboard today, how's everyone else's day going :D […]
Show full quote

Well I destroyed a perfectly good motherboard today, how's everyone else's day going 😁

I can confirm that the Machinist X99-PR9 does NOT have either of its PCH's LDRQ pins wired up anywhere.

I was hoping I could maybe re-use this motherboard as a media center PC in my living room but there's no way I'm getting this PCH back on, especially now I've sanded down the soldermask.

Bit of a shame but at least it wasn't expensive!

(BTW I wrote a utility to pulse the GPIO23 pin at 100hz to look for it on a scope (or speaker, heh). I was able to use it to find other GPIO pins on various resistors but not the magic GPIO23 (for obvious reasons). I'll post the source when I can dig it off the m.2 card that's currently in my machinist motherboard...)

What a pity.
Here, it can't hurt to ask them if they'd consider making a board revision that routes LDRQ to the LPC DEGUG header.
Hell, show them this thread, and ask if they might consider making a board with an ISA slot.

https://machinist.site/contact

And if they won't...

http://www.huananzhi.com/en/aq.php
http://jginyue.com/index.php?m=content&c=inde … =lists&catid=23

I'm sure there are more, but you get the point.

LDRQ(s) at a header with rest of LPC would make life easier for sure, especially with a BIOS that plays along.

RayeR wrote on 2024-04-24, 14:52:

Tiido, this forum holds a hundreds of leaked MB schematics, most of them are for Gigabyte so you're lucky man 😀
https://smd.db-x7.ru/load/skhemy_materinskikh … ma/287-1-0-3134
on my MB the resistor was not populated and I had to put down PCH heatsink to connect a wire on the pad. I hope that UEFI on you MB will not cause extra problems with IRQ/DMA. If you have LPT onboard you can reserve IRQ5/7 for legacy ISA by disabling LPT after boot. I wrote some utility for superIO settings but still not finished, just for my debugging...

Neat ~

The good thing about my ISA C2D machine is that it actually has IRQ and DMA reserve settings like old stuff did, the GB board definitely doesn't but there is COM and LPT on it so in the worst case I can do what you did. I do need to see if I can reliably run Win98SE or ME on it

About running wire under the PCH - Iphone 6 was very bendy, this resulted in breaking pads under Meson (touch). Those are pads very close to the edge and you arent going between the balls, yet repair is already a huge B. I dont see a home gamer succeeding with a wire going from 6 rows deep, and if you can do it you already make enough money to not even worry about sourcing another board that doesnt need that 😀

[iPhone 6 Plus Touch Disease a TRUE FIX for Classic Recurring Grey Bars] STS Telecom https://www.youtube.com/watch?v=U2UMCzP3S0o