Windows 98 and DMA

[Guest wsxedcrfv]

Ok, tell me if this is normal or expected. Motherboard is based on Intel 845 chipset. I've just re-installed the drivers (infinst_enu.exe) but I'm not seeing any change.

When I bring up the System Properties / Device Manager, and select Computer -> Properties -> View Resources -> DMA, the only piece of hardware showing up in the list is the "Standard Floppy Disk Controller" (using DMA channel 2). Right under it, using channel 4, is the "Direct memory access controller". Like I said, nothing else is showing up claiming to use DMA. No other piece of hardware that I can see in Device Manager is showing any DMA usage in their resources list (not even Intel 82801DB Ultra ATA storage controller). There is no DMA checkbox showing up for my DVD drive. No DMA checkbox showing up for the hard drive controller or the hard drives themselves. The Sil3114 SATA card properties shows no DMA in it's resource listing.

No (!) showing up in Device Manager. Most or all of the drivers used by the computer (system devices) are indicating they are using an intel driver (2002 or 2003 date).

DMA controller is using Intel driver 2-25-2002 (no conflicts). I've set check box for "Reserve DMA buffer 64kb" and check box for "restrict DMA transfers to memory below 4gb" but it made no difference.

Is this normal or expected?

[Sfor]

I do have a motherboard with Intel 845 chipset, as well. In the device manager there are just 4 entries. One for the FDD controller, one for DMA controller, ant two for Sound Blaster card.

In case of IDE drives, all DMA related settings are available in Intel Application Accellerator pannel. However, it does not cover SATA PCI controllers.

So, the effects you mentioned are quite normal, if you have a Intel Application Accellerator installed.

[Guest wsxedcrfv]

So, the effects you mentioned are quite normal, if you have a Intel Application Accellerator installed.

Ok, yes I do have IIA, and it's control panel says that my IDE and DVD drives are using some UDMA mode. But you wouldn't know it from looking at device manager.

So other than the floppy controller, no other device (on-board Davicom 9102 ethernet, on-board C-Media AC-97 audio, or USB controller, or Nvidia 4000 AGP video card) is using DMA. Is that normal?

[Sfor]

The truth is, other devices are using DMA (the best example is the IDE controller). Windows 98 does not report the real DMA usage, simply.

[rloew]

Ok, tell me if this is normal or expected. Motherboard is based on Intel 845 chipset. I've just re-installed the drivers (infinst_enu.exe) but I'm not seeing any change.

When I bring up the System Properties / Device Manager, and select Computer -> Properties -> View Resources -> DMA, the only piece of hardware showing up in the list is the "Standard Floppy Disk Controller" (using DMA channel 2). Right under it, using channel 4, is the "Direct memory access controller". Like I said, nothing else is showing up claiming to use DMA. No other piece of hardware that I can see in Device Manager is showing any DMA usage in their resources list (not even Intel 82801DB Ultra ATA storage controller). There is no DMA checkbox showing up for my DVD drive. No DMA checkbox showing up for the hard drive controller or the hard drives themselves. The Sil3114 SATA card properties shows no DMA in it's resource listing.

No (!) showing up in Device Manager. Most or all of the drivers used by the computer (system devices) are indicating they are using an intel driver (2002 or 2003 date).

DMA controller is using Intel driver 2-25-2002 (no conflicts). I've set check box for "Reserve DMA buffer 64kb" and check box for "restrict DMA transfers to memory below 4gb" but it made no difference.

Is this normal or expected?

The DMA Resources you are looking at are the numbered DMA Ports used by the standard DMA Controllers. Devices such as the Hard Drive Controllers have their own DMA Controllers and do not use the numbered DMA Ports.

[Sfor]

It does not have a sense. According to the ATA specification the DMA transfer commands do not contain memory addresses. So, the DMA tranfers have to be done through motherboard DMA controller, as a memory adress has to be passed for a DMA transfer to be performed.

I would rather say, the Windows displays just the DMA channels staticaly assigned to particular devices. All other channels can be used by any device, when necesary. So, the free motherboard DMA channels are used by any device in need of such a resource. Unlike IRQ, the available DMA channels are not staticaly assigned to particular devices.

Edited April 7, 2011 by Sfor

[rloew]

It does not have a sense. According to the ATA specification the DMA transfer commands do not contain memory addresses. So, the DMA tranfers have to be done through motherboard DMA controller, as a memory adress has to be passed for a DMA transfer to be performed.

I would rather say, the Windows displays just the DMA channels staticaly assigned to particular devices. All other channels can be used by any device, when necesary. So, the free motherboard DMA channels are used by any device in need of such a resource. Unlike IRQ, the available DMA channels are not staticaly assigned to particular devices.

The ATA Commands do not have addresses because the Hard Drives don't need to know where the Data Transfer Area is. The Addresses are sent to the DMA Controller on the Chipset or HDC Card.