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Which USB 2.0 cards for old motherboards

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Reply 60 of 68, by hyoenmadan

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swaaye wrote on 2014-05-01, 18:36:
smeezekitty wrote:
Logistics wrote:

Since 98SE introduced ACPI, I bet that is a possible problem. You can Google how to disable ACPI in 98SE and see if it helps.

Why would ACPI cause a problem?

Some motherboards had flawed ACPI implementations that caused strange problems and instability. It has been awhile since I've run into it though. ACPI usually works ok. 98SE will actually detect many problematic BIOSs and switch to APM mode during initial setup.

Actually some USB2.0 cards don't like to work in an ACPI-less environment (Because the WDM nature of the USB drivers themselves, very important if you are using some USB2.0 pack made with Winxp files on it). So keep that in account.
As rule of gold... Old NEC usb2 chipsets can wristband certain legacy limitations of older configurations. Them can work in old style interrupt systems (have the legacy interrupt pin... but them will eat 2 or 3 irqs, so take that in account), and in ACPI-less environments. VIA ones don't. Them require MSI interrupts, and sometimes will work acpiless, or not... depends in driver configuration, and if you are using "packs" for generic device support.

Reply 61 of 68, by Joseph_Joestar

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hyoenmadan wrote on 2021-02-10, 20:22:

Them can work in old style interrupt systems (have the legacy interrupt pin... but them will eat 2 or 3 irqs, so take that in account), and in ACPI-less environments.

This is my main gripe with using USB 2.0 cards on a Win9x/DOS rig. They take up too many IRQs and often don't allow you to change their values manually. This nearly always results in a conflict if you're using an ISA sound card.

On the other hand, a PCI network card only takes up one IRQ and you can usually choose which value it should use. It's an excellent alternative if file transfer speed is the main reason for wanting USB 2.0.

Using Audigy drivers with a Sound Blaster Live
Installing DOS drivers on an Audigy2 ZS
OPL3 vs. ESFM vs. CQM vs. SBLive
OPTi 82C930 review

Reply 63 of 68, by hyoenmadan

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Joseph_Joestar wrote on 2021-02-10, 20:32:

This is my main gripe with using USB 2.0 cards on a Win9x/DOS rig. They take up too many IRQs and often don't allow you to change their values manually. This nearly always results in a conflict if you're using an ISA sound card.

On the other hand, a PCI network card only takes up one IRQ and you can usually choose which value it should use. It's an excellent alternative if file transfer speed is the main reason for wanting USB 2.0.

Well... An USB2.0 PCI card is actually a multifunction PCI device, unlike a standard NIC card (here no Intel advanced stuff). Each "eaten" IRQ is used for one of these functions: In NEC's legacy case, 1 for each OHCI USB1.0 controller functions (cards have generally 2 of these, as each one supports only 2 physical ports, and no root hubs), and 1 for the EHCI USB2.0 function, which supports all the physical ports connecting them via a virtual root hub, which also connects the OHCI controller to physical via switches logic to detect the actual device "speed mode". VIA ones cut the need of one IRQ forcing the EHCI controller to use MSI style interrupts, but the legacy UHCI controllers still will use an IRQ each one, so you still need 2 in case of 4port cards. This small side effect means the card can be used in old configurations not compatible with MSI interrupts (if electrically compatible ofc), BUT ONLY in USB1.0 mode. But since UHCI standard is also more picky with PCI specific implementation things, these still can bug with some PCI chipsets. OHCI is more tolerant in this case too, so the NEC legacy USB2 chips still win even if you disable EHCI 2.0 speed mode to save one IRQ.

This is well known by ReactOS devs.

Reply 64 of 68, by malloc32

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I have two pci usb 2.0 (AliExpress), one has a via chip, the other has a Nec chip. Via doesn't work with my 430tx , video corruption, hangs the computer...., Nec's one work fine with my 430fx W95 and with my 430tx W98.

Reply 65 of 68, by B24Fox

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hyoenmadan wrote on 2021-02-13, 04:32:
Joseph_Joestar wrote on 2021-02-10, 20:32:

This is my main gripe with using USB 2.0 cards on a Win9x/DOS rig. They take up too many IRQs and often don't allow you to change their values manually. This nearly always results in a conflict if you're using an ISA sound card.

On the other hand, a PCI network card only takes up one IRQ and you can usually choose which value it should use. It's an excellent alternative if file transfer speed is the main reason for wanting USB 2.0.

Well... An USB2.0 PCI card is actually a multifunction PCI device, unlike a standard NIC card (here no Intel advanced stuff). Each "eaten" IRQ is used for one of these functions: In NEC's legacy case, 1 for each OHCI USB1.0 controller functions (cards have generally 2 of these, as each one supports only 2 physical ports, and no root hubs), and 1 for the EHCI USB2.0 function, which supports all the physical ports connecting them via a virtual root hub, which also connects the OHCI controller to physical via switches logic to detect the actual device "speed mode". VIA ones cut the need of one IRQ forcing the EHCI controller to use MSI style interrupts, but the legacy UHCI controllers still will use an IRQ each one, so you still need 2 in case of 4port cards. This small side effect means the card can be used in old configurations not compatible with MSI interrupts (if electrically compatible ofc), BUT ONLY in USB1.0 mode. But since UHCI standard is also more picky with PCI specific implementation things, these still can bug with some PCI chipsets. OHCI is more tolerant in this case too, so the NEC legacy USB2 chips still win even if you disable EHCI 2.0 speed mode to save one IRQ.

This is well known by ReactOS devs.

Thanks for shedding light on the subject! Very good info!