Interloper's best ISA card: https://www.interloper.com/products/details.p … 111153&cat=1244

IM7945 Socket 775 Motherboard
Pentium 4 socket 775 motherboard with 1 ISA slot, DMA support, Gigabit LAN

Processor Support:
Intel ® Core2 Quad (Q9000)
Intel ® Core2 Duo (E8000 and E7000)
Intel ® Core2 Extreme (QX9000)
Up to 4.0GHz speed and up to 12MB L2 cache
Chipset:
Intel ® Q45 Chipset
ICH10DO
FSB:
800MHz / 1066MHz / 1333MHz
Memory:
Four DDRIII sockets
Up to 8GB 800/1066MHz SDRAM, w/o ECC

Can it really work with DOS sound? Installation of Duke Nukem fits in L2 almost entirely

It says it supports DMA on the ISA slot so in theory it could have sound but it would be nice to have verification of what bridge chips it uses. From the looks of it, there's a Winbond PCI to ISA bridge chipset (it uses two parts, one for address+data, one for IRQ+DMA) but with the southbridge used, that particular chipset will not give DMA, only IRQs... I was unable to find a bigger image to actually see what chips are present on the board.

Tiido wrote on 2023-08-02, 11:27:

It says it supports DMA on the ISA slot so in theory it could have sound but it would be nice to have verification of what bridge chips it uses. From the looks of it, there's a Winbond PCI to ISA bridge chipset (it uses two parts, one for address+data, one for IRQ+DMA) but with the southbridge used, that particular chipset will not give DMA, only IRQs... I was unable to find a bigger image to actually see what chips are present on the board.

It seems that they used to install Winbond W83627DHG chip for LPC I/O.
It's left down side of page.

That is just a SuperIO chip, it will not deal with the ISA slots but PS/2, COM, LPT, floppy etc.

RayeR wrote on 2020-03-16, 17:16:

Where is the dedicated thread? […]
Show full quote

Where is the dedicated thread?

AFAIK Win10 dropped support of ISA subsystem from the kernel so ISA card may not work there but it could work in DOS.
The datasheet has better photo, from this I can read:
IT8892E - PCIe to PCI Bridge
F81866AD - LPC based superIO with 6x UART, LPT, FDC...
F85226AD - https://www.alldatasheet.com/datasheet-pdf/pd … TEK/F85226.html Yeah! the LPC2ISA bridge, not PCI2ISA as on 99% of other MBs. So there's a chance ISA sound would work there. So anyone has enough courage to waste his money and test it? 😀 I already wasted >300$ for Commell P4LA years ago (that turned out to have wrong bridge without ISA DMA...)

What do you think about another version, P4ELA in the manual it says "One ISA slots (without DMA supported)", has "W83628 + W83629" and ICH10

trannks wrote on 2024-06-18, 19:41:

What do you think about another version, P4ELA in the manual it says "One ISA slots (without DMA supported)", has "W83628 + W83629" and ICH10

Emphasis added. No. It's not possible to use DMA with PCI-ISA bridges for any board with ICH6 and beyond.

LSS10999 wrote on 2024-06-19, 00:31:

trannks wrote on 2024-06-18, 19:41:

What do you think about another version, P4ELA in the manual it says "One ISA slots (without DMA supported)", has "W83628 + W83629" and ICH10

Emphasis added. No. It's not possible to use DMA with PCI-ISA bridges for any board with ICH6 and beyond.

I saw in previous posts LDRQ is mentioned, and In ICH10 datasheet LDRQ is mentioned too.
ICH10 datasheet:
"Bus Master Device Mapping and START Fields
Bus Masters must have a unique START field. In the case of the ICH10 that supports
two LPC bus masters, it drives 0010 for the START field for grants to bus master #0
(requested via LDRQ0#) and 0011 for grants to bus master #1 (requested via
LDRQ1#.). Thus, no registers are needed to configure the START fields for a particular
bus master.
5.5 DMA Operation (D31:F0)
The ICH10 supports LPC DMA using the ICH10’s DMA controller. The DMA controller has
registers that are fixed in the lower 64 KB of I/O space. The DMA controller is
configured using registers in the PCI configuration space. These registers allow
configuration of the channels for use by LPC DMA"

The Winbond W83628+9 are not using any part of LPC for their ISA functionality so LDRQ related things don't matter at all for it.

Tiido wrote on 2024-06-19, 03:40:

The Winbond W83628+9 are not using any part of LPC for their ISA functionality so LDRQ related things don't matter at all for it.

Soldering wire from LDRQ to some corresponding pin to the W83628 is not an option? or maybe it requires an additional IC?
(LPC LDRQ is not the same as DRQ from W83628 datasheet?)

It requires ISARQ and ISAGNT signals seen on datasheet to do DMA on ISA slots, these are the signals found on SBlink/PC-PCI header, and they're only found on ICH5 and older chipsets. There is no use for any LPC signal to this chpset, it doesn't understand what LPC is (LDRQ is part of entire LPC bus and that signal alone won't do anything as rest of the transaction comes off the LPC bus still).

The DRQ pins are ISA side stuff and only do things once the SBlink pair is connected to W83629 chip which is what handles IRQs + DMAs for the ISA slots.

Tiido wrote on 2024-06-19, 19:44:

It requires ISARQ and ISAGNT signals seen on datasheet to do DMA on ISA slots, these are the signals found on SBlink/PC-PCI header, and they're only found on ICH5 and older chipsets. There is no use for any LPC signal to this chpset, it doesn't understand what LPC is (LDRQ is part of entire LPC bus and that signal alone won't do anything as rest of the transaction comes off the LPC bus still).

The DRQ pins are ISA side stuff and only do things once the SBlink pair is connected to W83629 chip which is what handles IRQs + DMAs for the ISA slots.

An idea, would a interposer pcb work to replace the W83629 with Fintek F85226? both are 128 pin, is the area of the interposer pcb enough to route the pins around? (Solder a pcb with the routed pins instead of W83629 and solder F85226 on the pcb, and connect the other things like LDRQ with wires)

I don't think you can interposer it, not only because of the very different pinout but on purely mechanical reasons. The pin pitch is 0.5mm and I'm unsure how would one get it soldered down to main PCB and then have a chip on top in the exact same footprint, and not just this one chip but the other Winbond one must be replaced too and get connections from the Fintek and I'm unsure how that could be done effectively. It would be a lot of very thin wires directly soldered to the pins of the chips in the worst case and maybe some kind of flex cable stuff in the better one but then I am unsure how you'll solder down the carriers to the motheboard since the flex part will obscure things and of course any zoo of parts that may be along the way...

On top of it, there's software related conf to do too before it even becomes available to use and it isn't fully straightforward due to possible IRQ conflicts due to BIOS assigning away IRQs to various other devices.

I think it is much easier to source another motherboard with the required functionality in it already or explore dISAppointment approach on a suitable board without any native ISA at all. That is what I am going to be doing eventually when I order some PCBs.

trannks wrote on 2024-07-18, 16:51:

An idea, would a interposer pcb work to replace the W83629 with Fintek F85226? both are 128 pin, is the area of the interposer pcb enough to route the pins around? (Solder a pcb with the routed pins instead of W83629 and solder F85226 on the pcb, and connect the other things like LDRQ with wires)

Fintek has a mention of a new chip with a kind of confusing name, F85526, that supposedly connects PCIe to ISA, while utilizing LDRQ# for ISA DMA.

It's been discussed in the dISAppointment thread before but at the time of discussion Fintek did not appear to have samples ready for review... so can't be sure how it'll really turn out, as well as reference designs.

If the chip in question can really function as advertised it would have achieved something similar to your idea, though it would be a completely new, different design.

Tiido wrote on 2024-07-18, 19:30:

On top of it, there's software related conf to do too before it even becomes available to use and it isn't fully straightforward due to possible IRQ conflicts due to BIOS assigning away IRQs to various other devices.

On modern motherboards, making specific legacy IRQ free can be a real problem due to the sheer amount of onboard PCI devices, as well as the lack of capability in BIOS to manually reserve IRQ lines for legacy purposes.

In case of my X99 board (on which I've a working dISAppointment setup with CT2950), IRQ5 was too contested to free, though I was able to free IRQ7 by disabling onboard audio as for some reasons the board placed it on an exclusive PIRQ line separate from others. For other boards, your mileage may vary.