tehsiggi wrote on 2026-09-28, 12:29:

Nexxen wrote on 2026-09-28, 11:55:

tehsiggi wrote on 2026-09-28, 11:45:

So lunch break was very fruitful. […]
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So lunch break was very fruitful.

The idea to remove the GPU VRM from the HD3450 AGP was a mistake. It appears the 1.2V from it are used for the Rialto bridge as well. Which is interesting, since the normal HD3450 uses 1.1V - so they bumped the VDDC to re-use that voltage for Rialto.

I just fed it from one of my lab supplies and it is loaded with around 0.75A - which is not nothing.
So I went ahead now and put the VRM back in.

However the most important discovery:
The HD3450 PCIe gets enumerated through my zombie HD3450 connected by PCI x1 - can't use it, but this is already a good sign. Cross changing to an X700 causes POST stuck at code 25 - so it looks like rialto is doing some lookup. More to investigate. But before I go ahead and wire 16 PCIe lanes, I think I'll roll out a PCB with a rialto on it. fun times ahead..

The attachment rialto_jankfest.jpeg is no longer available

Way to go..

The attachment rialto_hd3450_halfway.jpeg is no longer available

I thought the documentation on the Rialto to be widely available.
Interesting work. This is SF tinkering 😀

One would think Rialto is already "open" in a sense of information. But no. The BIOS parts are basically unknown (well, not to me that much anymore) - and hardware wise there's also a lot of unknowns.

So I'm doing the digging now - step by step..

Yep, this is work bit by bit. No pun intended.
I'm curious to know how it ends. Maybe open a dedicated thread.

Nexxen wrote on 2026-09-28, 12:45:

tehsiggi wrote on 2026-09-28, 12:29:

Nexxen wrote on 2026-09-28, 11:55:

I thought the documentation on the Rialto to be widely available.
Interesting work. This is SF tinkering 😀

One would think Rialto is already "open" in a sense of information. But no. The BIOS parts are basically unknown (well, not to me that much anymore) - and hardware wise there's also a lot of unknowns.

So I'm doing the digging now - step by step..

Yep, this is work bit by bit. No pun intended.
I'm curious to know how it ends. Maybe open a dedicated thread.

It'll get a thread and everything will land on github.

Read here somewhere that there was no evidence that SB-LINK (PC-PCI) can work on VIA chipsets, so decided to try myself, I have an EPOX EP-MVP3G2 super socket 7 with VIA MVP3 chipset that has a SB-LINK header and got recently a Yamaha 724 PCI also with the SB-link header.

Very painful to say the least, started with driver version 3.06 and it would not allow me to enable Sound Blaster functionality at all, with no reasonable explanation, moving to version 3.16 helped, I could now enable SB, but was getting IRQ errors.
Tried every possible BIOS settings to make sure IRQ and DMA were correctly assigned.
As I don't have a proper SB-Link cable I was using dupont cables, like demonstrated on Scrap Computing video about SB-Link, check the connections a million times, but still same error.
Decided to use a Flat cable that I had on hands, and it finally worked, could now run all diags on Yamaha setupds app, 16-bit, 8-bit and FM.
I can now confirm that SB-Link actually works with VIA chipsets, tried several games in it ran perfectly.

Last issue I'm facing is that sometimes when I reboot the system I need to run setutds twice to activate SB-Link

Had to unfortunately scrap an ASUS AH4650 AGP.

Turns out Rialto bridge died.

I have no BGA tools nor any shops locally will touch any BGA work that isn't from high paying industrial contracts, so I just went and salvaged whatever usable from it (cooler, backside bracket + screws) and to scrap it went.

PcBytes wrote on 2026-09-28, 18:36:

Had to unfortunately scrap an ASUS AH4650 AGP.

That is unfortunate. What dissuades you from learning to do BGAs?

I haven't developed the skills yet but I'm not scrapping mine. If I can't fix one then I put it aside for the day that I can. I have quite a few to work through 😉

For my retro activity, I don't get much time alone with the hardware itself, so I did more sleuthing on archive.org while others watched TV and surfaced a lot of interesting new facts about my old devices.

MattRocks wrote on 2026-09-28, 19:18:

That is unfortunate. What dissuades you from learning to do BGAs? […]
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PcBytes wrote on 2026-09-28, 18:36:

Had to unfortunately scrap an ASUS AH4650 AGP.

That is unfortunate. What dissuades you from learning to do BGAs?

I haven't developed the skills yet but I'm not scrapping mine. If I can't fix one then I put it aside for the day that I can. I have quite a few to work through 😉

For my retro activity, I don't get much time alone with the hardware itself, so I did more sleuthing on archive.org while others watched TV and surfaced a lot of interesting new facts about my old devices.

Tool costs. Cheapest BGA setup would set me back close to 520-530 euros, a price far too big to consider.

Crossed the actual Rialto bridge in Venice a couple of times.

PcBytes wrote on 2026-09-28, 20:50:

MattRocks wrote on 2026-09-28, 19:18:

That is unfortunate. What dissuades you from learning to do BGAs? […]
Show full quote

PcBytes wrote on 2026-09-28, 18:36:

Had to unfortunately scrap an ASUS AH4650 AGP.

That is unfortunate. What dissuades you from learning to do BGAs?

I haven't developed the skills yet but I'm not scrapping mine. If I can't fix one then I put it aside for the day that I can. I have quite a few to work through 😉

For my retro activity, I don't get much time alone with the hardware itself, so I did more sleuthing on archive.org while others watched TV and surfaced a lot of interesting new facts about my old devices.

Tool costs. Cheapest BGA setup would set me back close to 520-530 euros, a price far too big to consider.

Heh, my late noughties "BGA Setup" was a $10 on sale paintstripper gun (With a low setting) a meat thermometer with remote probe, nozzles made out of thick foil pie plates and drink cans held on with wire, and I made it extra sophisticated when I got a $5 stand for a handheld drill and put the heatgun on that, and aquired an early IR reading thermometer that didn't need a probe. Oh yeah, also needed an inkjet refill bottle well rinsed out with the long needle top for applying flux.

BitWrangler wrote on 2026-09-29, 21:54:

PcBytes wrote on 2026-09-28, 20:50:

MattRocks wrote on 2026-09-28, 19:18:

That is unfortunate. What dissuades you from learning to do BGAs?

I haven't developed the skills yet but I'm not scrapping mine. If I can't fix one then I put it aside for the day that I can. I have quite a few to work through 😉

For my retro activity, I don't get much time alone with the hardware itself, so I did more sleuthing on archive.org while others watched TV and surfaced a lot of interesting new facts about my old devices.

Tool costs. Cheapest BGA setup would set me back close to 520-530 euros, a price far too big to consider.

Heh, my late noughties "BGA Setup" was a $10 on sale paintstripper gun (With a low setting) a meat thermometer with remote probe, nozzles made out of thick foil pie plates and drink cans held on with wire, and I made it extra sophisticated when I got a $5 stand for a handheld drill and put the heatgun on that, and aquired an early IR reading thermometer that didn't need a probe. Oh yeah, also needed an inkjet refill bottle well rinsed out with the long needle top for applying flux.

Funny enough, I managed to somewhat fix (at least I never saw the fault again) a motherboard from an IBM Thinkpad T43, which would alway freeze on me, if I flexed the chassis. I did this in the oven - motherboard without CMOS battery wrapped in tin foil, and temperature and time as per an instruction I found online. May've been dumb luck, but nevertheless ..

H3nrik V! wrote on 2026-09-30, 06:16:

Funny enough, I managed to somewhat fix (at least I never saw the fault again) a motherboard from an IBM Thinkpad T43, which would alway freeze on me, if I flexed the chassis. I did this in the oven - motherboard without CMOS battery wrapped in tin foil, and temperature and time as per an instruction I found online. May've been dumb luck, but nevertheless ..

FWIW - what I prefer to do in cases like this is to try and identify as much as possible the exact area of the board where the fault is located - if the board in sensitive enough that flexing the chassis causes a failure - more directed pressure on various areas/chips will usually "close in")

and then use a hot air gun to (Carefully) reflow that section of the board.

Fixed an old derelict ASUS K7M using the "corpse" of the one I bought untested recently. Turns out Q16 was the culprit on the derelict one causing dead fans 🤣

Did have to dig up for the boardview to figure Q16 out though.

PcBytes wrote on 2026-09-30, 17:49:

Fixed an old derelict ASUS K7M using the "corpse" of the one I bought untested recently. Turns out Q16 was the culprit on the derelict one causing dead fans 🤣

Did have to dig up for the boardview to figure Q16 out though.

Is that a quad flat pack? What was your strategy to narrow that down?

Kahenraz wrote on 2026-09-30, 19:20:

PcBytes wrote on 2026-09-30, 17:49:

Fixed an old derelict ASUS K7M using the "corpse" of the one I bought untested recently. Turns out Q16 was the culprit on the derelict one causing dead fans 🤣

Did have to dig up for the boardview to figure Q16 out though.

Is that a quad flat pack? What was your strategy to narrow that down?

Q16 is the MOSFET responsible for (surprise) ALL fan headers onboard. It's the one above all three RAM slots.

More fiddling with the Thrustmaster PFCS and WCS Mark II - which are lovely devices, but do require a number of cables and finding mirrors of old software to get it to work on a more recent pentium II.

USB does make things a bit easier, but that would be no fun, would it? The ability to map buttons to keys is great, just a pity it isn't obvious how to *unmap* them.

I was going through old stuff, manuals, game notes and found these 2 pages.

Cool find. I remembered the SPISPOPD story but forgot the details and some probably never knews.
It is also available online:
https://www.doomgate.de/spispopdfaq.html
https://www.theoldcomputer.com/forum/viewtopi … php?f=35&t=4082

Messing about in dos with troublesome irongate GA-7IXE4 which has two ISA slots. Got athlon 1200 working in it. Paired with quadro2 pro and ess 1868f+x2gs. Dos games stuttering. Has to use fastvid and univbe + nvpatch. Got shadow warrior and duke3d running smoothly. Win 98 install next and looking to see if it's stable, then maybe throttle blaster it if I can get around sourcing the parts and soldering it...

gmaverick2k wrote on Today, 20:31:

Messing about in dos with troublesome irongate GA-7IXE4 which has two ISA slots. Got athlon 1200 working in it. Paired with quadro2 pro and ess 1868f+x2gs. Dos games stuttering. Has to use fastvid and univbe + nvpatch. Got shadow warrior and duke3d running smoothly. Win 98 install next and looking to see if it's stable, then maybe throttle blaster it if I can get around sourcing the parts and soldering it...

It's such an odd board. Did you recap it yet? I had to spend ages with mine replacing all of those 25v 330uF capacitors dotted all over the board on every rail.