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ISA slot motherboards from AliExpress

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Reply 60 of 87, by RayeR

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LSS10999 wrote:

Some useful information for ISA chipsets were compiled in this page.

I see, but it's related to old MBs and chipsets, not mention any modern PCI-E based MBs...

LSS10999 wrote:

This looks interesting. But I don't understand this:
The DMA controllers can initiate transfers
between the LPC and host bus. This provides the option of
adding an LPT or fl oppy controller to the LPC port with DMA
support. But the chipset DMA controller cannot initiate
PCI to host bus transactions. To enable ISA-conform DMA,
the ITE 8888 PCI to ISA bridge integrated on the Kontron
MICROSPACE® MSM-eO(-N) features two additional 8237
DMA controllers.

They admit LPC can do ISA DMA - that is what we need for soundcards but then they write "chipset DMA controller cannot initiate
PCI to host bus transactions" - is it needed? Maybe only for this AMD platform but for Portwell Ruby is the LPC2ISA bridge all that is needed and proved it works (at least on G41+ICH7)

LSS10999 wrote:

EDIT: Should comment that IMBA-G412ISA is also not quite flexible. It doesn't have any option to tweak CPU settings (multiplier, Vcore, etc.), and it couldn't handle 771-modded Xeons properly. I tried a few Xeons (E5450/E0, X5460/C0, X5470/E0) and while they do boot, the system becomes unstable with program crashes (sometimes the CPU could even miscalculate CRC) and sooner or later BSoD with a random error code.

Yes, industrial MBs don't include overclocking options. Do you have a related microcode in BIOS for your Xeon CPU?

BTW I just found this PC/104 http://c1170156.r56.cf3.rackcdn.com/UK_ADL_MM … IO-R-01_2DS.pdf expansion board by Adlink using the same Fintek LPC2ISA so if some wiring would be done to LPC header on MB and from PCI/104 pin connector to an ISA slot it might work. But I couldn't find any e-shop offering this board and no idea about price. I would expect a nasty $$$ for industrial HW...

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Reply 61 of 87, by LSS10999

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RayeR wrote:

I see, but it's related to old MBs and chipsets, not mention any modern PCI-E based MBs...

It did reference the Intel document about the removal of PC/PCI in recent ICH chipsets, stating it's game overfor ISA sound cards unless you only use the synth, which is the case. Most of the page focused on boards and chipsets that are reported working well with ISA sound cards.

RayeR wrote:
This looks interesting. But I don't understand this: The DMA controllers can initiate transfers between the LPC and host bus. Th […]
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This looks interesting. But I don't understand this:
The DMA controllers can initiate transfers
between the LPC and host bus. This provides the option of
adding an LPT or fl oppy controller to the LPC port with DMA
support. But the chipset DMA controller cannot initiate
PCI to host bus transactions. To enable ISA-conform DMA,
the ITE 8888 PCI to ISA bridge integrated on the Kontron
MICROSPACE® MSM-eO(-N) features two additional 8237
DMA controllers.

They admit LPC can do ISA DMA - that is what we need for soundcards but then they write "chipset DMA controller cannot initiate
PCI to host bus transactions" - is it needed? Maybe only for this AMD platform but for Portwell Ruby is the LPC2ISA bridge all that is needed and proved it works (at least on G41+ICH7)

LPC DMA remained in order to avoid breaking support for FDC and ECP parallel ports provided by SuperIO chips, which might be required for industrial purposes. If LPC DMA were removed, modern board would NEVER be able to support floppy drives and parallel ports anymore.

Guess that the "chipset DMA controller cannot initiate PCI to host bus transactions" is what breaks most of the legacy compatibility in ICH6 or later. It not only breaks PCI-ISA, it also breaks whatever sound cards used to support legacy DOS audio (except Aureal Vortex series). In modern AMD chipsets (like 700/800/900 series) the situation is much worse that it's behaving the same way as the Intel chipsets without native PCI (some 5 to 7 series PCHs and all PCHs from 8 series onwards), the legacy functions is completely inaccessible even after loading TSRs (and probably under Windows and Linux as well). It's that fact that makes the AMD/AMI's "ISA DMA virtualization" thing interesting.

From the IT8888 datasheet the PCI-ISA bridge itself does feature 8237 DMA controllers of its own, most likely those are what actually mediate the transactions between the ISA devices and the chipset PC/PCI, though I'm not entirely sure. The PCI-ISA bridges' DMA related pins might have been connected to somewhere even in modern (ICH6+ based) motherboards, though it's not easy to find that out on a PCB that complex.

RayeR wrote:

Yes, industrial MBs don't include overclocking options. Do you have a related microcode in BIOS for your Xeon CPU?

I did insert microcodes into the BIOS. It's just that the board probably has some underlying BIOS or wiring issues (or maybe power management related) that makes things incompatible with LGA771 Xeons. The board recognizes the Xeon correctly, and it can stay running under DOS and other system diagnostic programs for quite a while (I could run MemTest+ with two or more passes without issues), just it would crash once in a while with a different BSoD under Windows. Sometimes it can even miscompute things, causing CRC and data errors that goes away the next time the program runs, and after crash, keyboards would sometimes stop responding the next boot, requiring a hard reset to get the keyboard back running.

It seems most insudstrial motherboards aren't meant to be used to run out-of-spec stuffs. I also tried modding the BSEL of a Pentium D 965 from 266 (LLL) down to 200 (LHL) for a 865-based motherboard (IMB200) in hope it can boot properly, but still not successful. No matter the mod, the board would either not post or give it an incorrect, non-bootable bus clock (used to be 33MHz, this time I managed to make it 40MHz).

The only purpose for those boards is to provide additional I/O ports that consumer motherboards hardly provide (RS232/485/422, ECP Parallel, GPIO, etc.), yet still very useful in industrial purposes. They only support whatever hardware the document mentions, and that'd be the end of the line.

RayeR wrote:

BTW I just found this PC/104 http://c1170156.r56.cf3.rackcdn.com/UK_ADL_MM … IO-R-01_2DS.pdf expansion board by Adlink using the same Fintek LPC2ISA so if some wiring would be done to LPC header on MB and from PCI/104 pin connector to an ISA slot it might work. But I couldn't find any e-shop offering this board and no idea about price. I would expect a nasty $$$ for industrial HW...

I'm not sure about the possibility given the board itself might be rare. For desktop motherboard, the TPM header, which is often left unused, is connected to the MB using LPC, and might be able to be used for other purposes. It's just how the wiring would turn out...

Reply 62 of 87, by RayeR

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LSS10999 wrote:

It did reference the Intel document about the removal of PC/PCI in recent ICH chipsets, stating it's game overfor ISA sound cards unless you only use the synth, which is the case. Most of the page focused on boards and chipsets that are reported working well with ISA sound cards.

Yes, I know and refer this document also on my site. But we know that Portwell Ruby is at least one MB based on newer PCI-E chipset with ICH7 that is proved to work fine with Soundblaster (TmEE). So I belive the same approach with LPC2ISA bridge can be replicated on all newer MBs (without use of PCI2ISA bridge). But I didn't found any newer MB with this fintek LPC2ISA bridge... BTW AMD was good with sound HW virtualization long time ago on their's Geode MBs where they emulated SB on AC'97 in SMM via VSA (part of proprietary BIOS binary blob). I have one such thin client Compaq Evo T20: http://rayer.g6.cz/hardware/evo-t20.htm and you can see a short part of the Boost demo running on this PC with sound: http://rayer.g6.cz/hardware/evo-t20/boostdmo.avi
The major problem is that this thin client doesn't have PS/2 KB (it's missing a superIO chip at all) but only USB and I didn't find a working USB driver for DOS. It has crappy proprietary BIOS without SETUP that's missing USB KB legacy emu. It's quite weird it contains SB emu but no KB emu. But it was designed to run Windows NT (embedded) or CE not DOS...

LSS10999 wrote:

I did insert microcodes into the BIOS. It's just that the board probably has some underlying BIOS or wiring issues (or maybe power management related) that makes things incompatible with LGA771 Xeons.

Maybe it's also poor VRM design that cause some excessive Vdrops or Vripple on Vcore during heavy load transients. AFAIK those LGA771 Xeons have TDP 125W that is more than desktop C2D or C2Q (65/95W). Memtest SW gerenates quite constant Vcore loading so if it's ballancing on the edge the system may behave stable but as you run real-work apps with highly variable CPU load it may fail. If you have some DSO you can try to monitor Vcore on some pins and compare it with a less TDP CPU.

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Reply 63 of 87, by LSS10999

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RayeR wrote:

Yes, I know and refer this document also on my site. But we know that Portwell Ruby is at least one MB based on newer PCI-E chipset with ICH7 that is proved to work fine with Soundblaster (TmEE). So I belive the same approach with LPC2ISA bridge can be replicated on all newer MBs (without use of PCI2ISA bridge). But I didn't found any newer MB with this fintek LPC2ISA bridge... BTW AMD was good with sound HW virtualization long time ago on their's Geode MBs where they emulated SB on AC'97 in SMM via VSA (part of proprietary BIOS binary blob). I have one such thin client Compaq Evo T20: http://rayer.g6.cz/hardware/evo-t20.htm and you can see a short part of the Boost demo running on this PC with sound: http://rayer.g6.cz/hardware/evo-t20/boostdmo.avi
The major problem is that this thin client doesn't have PS/2 KB (it's missing a superIO chip at all) but only USB and I didn't find a working USB driver for DOS. It has crappy proprietary BIOS without SETUP that's missing USB KB legacy emu. It's quite weird it contains SB emu but no KB emu. But it was designed to run Windows NT (embedded) or CE not DOS...

That's impressive, even though the VSA might be very chipset-specific. Dunno if VSA includes support for FM OPL though, I couldn't find anything from the geode-vsa source code, only about the audio (XpressAUDIO), probably there isn't. From the demo the SB16 emulation sounds excellent.

RayeR wrote:

Maybe it's also poor VRM design that cause some excessive Vdrops or Vripple on Vcore during heavy load transients. AFAIK those LGA771 Xeons have TDP 125W that is more than desktop C2D or C2Q (65/95W). Memtest SW gerenates quite constant Vcore loading so if it's ballancing on the edge the system may behave stable but as you run real-work apps with highly variable CPU load it may fail. If you have some DSO you can try to monitor Vcore on some pins and compare it with a less TDP CPU.

Apparently it's not just the 120W ones. The 80W E5450 also fails after a while. It's possible that there really are some VRM issues with the board causing problems with those modded LGA771 CPUs. LGA775 ones (like Q9650, 95W) work fine and stable though. Replacing the PSU with a more reliable one eased the BSoDs to the point that it'd only crash while inside the OS and could live through the OS installation process.

The board also doesn't have features to disable SpeedStep, which might be the cause of the fluctuating readings of Vcore under CPUZ, and the possible cause of all those BSoDs, even when I manually set minimum performance to 100% in Power Options. The undervolting still happens even when the CPU clock is kept at maximum (probably due to Vdrops). When under real workload, the CPU would randomly miscalculate and corrupt things, such as detecting corruptions when there isn't (like driver installers reporting CRC errors when the file was correct, and the installer extracts successfully upon the next attempt), causing memory-related BSoDs, etc.

EDIT: Happened to find a document about ISA DMA Support for congatec conga-EAF (an ETX computer-on-module based on AMD G-series APU) which mentioned that AMD's ISA DMA emulation uses SMIs (system management interrupts). So it's possible the legacy of VSA is still there on some modern embedded solutions, and that it has always been possible to emulate such through the use of SMIs to bridge legacy compatibility, just that the nature of SMI may result it impractical for certain industrial uses that requires strict timing.

Reply 64 of 87, by RayeR

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Hi,
as I mentioned about LPC here some time ago I have some progress on my project of LPC bus SuperIO expander http://rayer.g6.cz/hardware/lpc_sio.htm
I'm waiting for 5 PCBs from China now.
The question is if and how various OS can work with floppy controller when SuperIO is set to nonDMA mode (I assume that I will be able to configure it for usual legacy IO address so only difference will be in DMA because TPM header doesn't have LDRQ# signal routed on a pin). Is there some kernel config or patches at least for Linux? Maybe it will require a TSR or BIOS ROM module extension for DOS.
I know that HW part is quite easy but FW/SW work will be more complicated. It's just a testing prototype and challenge for me to make floppy live again in a modern PC (no I don't like floppy on USB).

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Reply 65 of 87, by RayeR

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LSS10999 wrote:

EDIT: Happened to find a document about ISA DMA Support for congatec conga-EAF (an ETX computer-on-module based on AMD G-series APU) which mentioned that AMD's ISA DMA emulation uses SMIs (system management interrupts). So it's possible the legacy of VSA is still there on some modern embedded solutions, and that it has always been possible to emulate such through the use of SMIs to bridge legacy compatibility, just that the nature of SMI may result it impractical for certain industrial uses that requires strict timing.

As I read that document I think they only used SMI for emulating ISA DMA but not a complete VSA SB emulation. (VSA doesn't require real SB it's emulating on onboard AC'97 codec). I think that VSA is quite a complicated, large and system dependent piece of code that would require a lot of programmers work to maintaind and support new platforms. As customers are mostly not interested/not paying enough for such feature the manufacturer cut the cost of devel. and derecate the VSA. That's a pity they didn't released it as an opensource so it might be included into Coreboot project and volunteeers could continue developing it. But it's sad reality of current closed hw/sources world...

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Reply 66 of 87, by LSS10999

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RayeR wrote:
LSS10999 wrote:

EDIT: Happened to find a document about ISA DMA Support for congatec conga-EAF (an ETX computer-on-module based on AMD G-series APU) which mentioned that AMD's ISA DMA emulation uses SMIs (system management interrupts). So it's possible the legacy of VSA is still there on some modern embedded solutions, and that it has always been possible to emulate such through the use of SMIs to bridge legacy compatibility, just that the nature of SMI may result it impractical for certain industrial uses that requires strict timing.

As I read that document I think they only used SMI for emulating ISA DMA but not a complete VSA SB emulation. (VSA doesn't require real SB it's emulating on onboard AC'97 codec). I think that VSA is quite a complicated, large and system dependent piece of code that would require a lot of programmers work to maintaind and support new platforms. As customers are mostly not interested/not paying enough for such feature the manufacturer cut the cost of devel. and derecate the VSA. That's a pity they didn't released it as an opensource so it might be included into Coreboot project and volunteeers could continue developing it. But it's sad reality of current closed hw/sources world...

The VSA has been open-sourced in 2006 under LGPL, with coreboot having its own OpenVSA based on it. However, it appears to be far from complete and there were little intent to extend this feature to modern chipsets. I think it's merely for supporting VSA-capable Geode systems on coreboot.

There's little need for Sound Blaster and other stuffs on those embedded modules, but ISA DMA might be needed in some appliances (which is why Intel 8xx industrial boards are still available to some extent, for customers who specifically need ISA DMA for certain devices). So far only AMD/AMI has the ability to utilize SMI to replicate ISA DMA functionalities which eliminates DMA related limitations at the expense of system responsiveness.

I'm not sure about the inner details of the VSA, but from the code it definitely looks like being highly chipset-specific as given the processing power of the CPUs at that time, it might not be practical to create such in a higher-level, more universal manner.

Reply 67 of 87, by RayeR

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LSS10999 wrote:

The VSA has been open-sourced in 2006 under LGPL, with coreboot having its own OpenVSA based on it. However, it appears to be far from complete and there were little intent to extend this feature to modern chipsets. I think it's merely for supporting VSA-capable Geode systems on coreboot.

Aha, I didn't know. OK, it seems to be too complex and complicated that nobody was able to port it to support intel HDA chips and intel ICH/PCH 🙁
Maybe it also requires some special HW feature of AMD Geode chipset that inte ICH/PCH is missing...

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Reply 68 of 87, by ChrisR3tro

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Guys, I just recently bought an iEi IMBA-G412ISA-R20 on eBay just out of curiosity if it would work with older ISA sound cards that need DMA transfers. The BIOS setup in the manual looked promising as it had an ISAPnP page for reserving IRQs and (even) DMA channels for legacy devices. I reserved IRQs 5&7 and DMA channels 1 & 5. The board itself has the ITE8888 PCI-to-ISA bridge.

You can see my test setup in the pictures. I tested with two different non-PnP SB16 and used the game Descent and DIAGNOSE.EXE from the SB16 drivers to try and play digitized sound.

As expected Adlib music works fine, but (AND NOW WE CAN FINALLY SETTLE THIS) digized sound DOES NOT WORK.
What I did to verify this:

  • Tried both ISA slots of the G412ISA boards.
  • Used two different SB16 that worked fine in an older machine with proper ISA bus.
  • Tried with the Setup utility of the DOS game Descent - OPL music works fine, no digitized sound...
  • Tried DIAGNOSE.EXE. I/O port, IRQs were set successfully, but DMA setting always failed. Also tried manually and "Auto Scan" - no success.

If you guys know something I could try, please tell me. Although I have little hope. Holding on to this board for a while, but ultimately I'll sell it again for hopefully a comparable price. I paid around 100 $.

Regards
locutus

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Reply 71 of 87, by Tiido

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This board has a PCI to ISA bridge and these require chipset support to do DMA, and that support ends with ICH5 south bridge.

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Reply 72 of 87, by imi

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hmm? why would they then specifically support DMA in bios, and there's a lot about DMA in datasheets about ICH8 too for example... I haven't gone deep diving yet because I'm still waiting for a CPU for my board before I can play around with it.

Reply 73 of 87, by Tiido

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I wouldn't know why the BIOS has these things but a PCI based bridge requires two signals in particular for DMA to work, which are deleted on chipsets after ICH5. The same signals are also present on PC/PCI aka SBlink connector.

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
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Reply 75 of 87, by imi

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I thought that is what the ISA bridge is supposed to do, I don't get why on my motherboard for example they would specifically include the DMA/Bus Mastering chip that isn't even needed if there was no way to make it work?

PC/PCI DMA is not supported on ICH6 onwards according to this, like Tiido said

PC/PCI DMA
The PC/PCI DMA protocol is supported on all I/O Controller Hubs from ICH to ICH5 (excluding 6300ESB). These parts have dedicated Request and Grant signals – REQ[A:B] and GNT[A:B] – to implement he hardware aspect of the protocol.
From ICH6 onwards these signals have been removed and, therefore, these devices no longer support the PC/PCI protocol. As a result, it is no longer possible to support ISA DMA or Bus Master transactions using a PCI/ISA bridge. A system designer should be aware of this limitation before using such a bridge.

LPC/ISA Bridge
The Low Pin Count (LPC) bus offers a second method of connecting an ISA bridge to an ICH. LPC can be seen, in some ways, as a successor to ISA since it offers a way to connect low bandwidth and legacy peripherals to the system. Although LPC has substantially fewer signals than ISA it exceeds the bandwidth due to the fast bus speed and modern protocol. There are limitations, however, in the LPC interface of Intel® Express chipsets that could limit the usefulness of a LPC to ISA bridge in the system’s application. System designers should be aware of these limitations before proceeding with their design.

Memory Transactions The ISA protocol allows for memory-mapped transactions to components placed on the bus. In order to support […]
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Memory Transactions
The ISA protocol allows for memory-mapped transactions to components placed on the bus. In order to support these transactions it is, therefore, necessary to support memory-mapped transaction on the LPC bus.
The LPC specification specifies that such transactions are supported on the LPC bus.
Indeed, on all I/O Controller Hubs up to and including ICH5 support these transactions. From ICH6 onwards, however, support for these transactions has been removed. As a result, it is not possible to support ISA memory mapped transactions on an Intel® Express chipset.

also found this older thread: PCie-to PCI, PCI to ISA, # of slots multipliers - bridges, risers, backplanes, research, especially for DOS, WIP.

my board has an ICH8M, going to try anyways x3

also @Tiido, what I've been reading from other threads and sites you got it working on a board with G41 and ICH7?

Reply 76 of 87, by RayeR

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RayeR wrote on 2017-12-04, 11:31:

Maybe it also requires some special HW feature of AMD Geode chipset that inte ICH/PCH is missing...

Ah, remembered my old post. I investigated SMM capabilities a bit but unfortunatelly I found that on intel chipsets that I checked the datasheet there is no possibility to configure SMI triggeer to legacy SB I/O adddress neither there is any configurable trigger register. It only allows trigger SMI by keyboard controller IO address to allow USB keyboard emulate legacy kbd for old systems. So it seems that AMD geode only has thay feature that made posssible VSA to work but this way is irrelevant for modern chipsets.

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Reply 77 of 87, by Tiido

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imi wrote on 2020-04-25, 20:12:

also @Tiido, what I've been reading from other threads and sites you got it working on a board with G41 and ICH7?

My board, RUBY9719VG2AR, has LPC to ISA bridge on it rather than PCI to ISA, and it is the only reason things could work, except that only limited amount of IO ranges are possible to be forwarded to the ISA bus which limits what can be used effectively. Only 4x consecutive IO ranges can be passed (up to 256 ports on 256 port alignments) and an util I made chooses best set to gain SB, MPU401, Adlib and some level of ISA PnP compatibility, since default settings on the board don't permit much to work.
Later chipsets delete few more signals from the spec, disallowing DMA to work even with LPC... I don't remember at which chipset that happened, but it certainly puts upper limit to where ISA DMA can still be had. Not so long ago there was a new board with an ISA slot shown on some PC news sites, and it apparently is using a chipset where DMA cannot be done on LPC side (and certainly not on PCI side).

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜

Reply 78 of 87, by imi

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I have two boards to try it with,
a GME965/ICH8M board with W83628F & W83629D ISA bridge chipset and from what I read the W83629D is specifically there to provide DMA functionality.
still looking for a CPU, if I can't find one soon I'll probably salvage one from a laptop before I go spending more on this.

the other is a Q77 board with ITE8888? bridge, this one has a damaged socket that I'll have to try and repair first (only reason I got it for cheap ^^)

once I get to it I'll definitely post my findings.

edit: to what you posted in the other thread, Q77 does support LDRQ on the LPC bus according to the datasheet.

LPC Serial DMA/Master Request Inputs:
LDRQ[1:0]# are used to request DMA or bus master access. These signals are typically connected to an external Super I/O device. An internal pull-up resistor is provided on these signals.
LDRQ1# may optionally be used as GPIO23.

Reply 79 of 87, by Tiido

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I used to have a board named BCM875PLG that used the same Winbond bridge chips and it is still a PCI to ISA type, and does require PC/PCI support signals for DMA to work. W83629D deals with the DMA and IRQ signals, essentially turning a PC/PCI header signals into full set of ISA control signals.
EDIT: Q77 has full LPC bus, but it doesn't help the ITE8888 as it expects PC/PCI DMA signals and not LPC ones (they are not compatible with one another unfortunately)

T-04YBSC, a new YMF71x based sound card & Official VOGONS thread about it
Newly made 4MB 60ns 30pin SIMMs ~
mida sa loed ? nagunii aru ei saa 😜