NEC AD-7191A stuck in PIO MODE




My NEC AD-7191A DVD burner is “stuck” in PIO Mode on Windows. I’m checking the Secondary IDE Channel Properties and although I have the “DMA if available” setting activated, the “Current Transfer Mode” is PIO Mode for my dvd burner.

I also checked the boot screen (in text mode) and the DVD writer shows as PIO 4 UltraDMA 4 mode, so I guess that it is the operating system that isn’t handling the drive correctly.

Is there anything I can do in order to have the proper DMA mode set?

Best regards.


You could try removing the IDE controller from device manager, reboot and allow Windows to reinstall the driver.
Also worth checking.
If your IDE controller can use the standard MS IDE drivers, this has been proved many times to work the best with optical drives.

This drive also requires an 80 conductor IDE cable to get the drive into UDMA mode 4.


Ok, I did manage to solve the PIO mode issue by uninstalling and reinstalling the IDE controller.

Now I have another problem: I have the Optiarc dvdrw unit (master) and a TEAC cdrw unit (slave) connected to the same IDE cable. The Optiarc is working in UDMA66 (PIO4 UDMA4) mode and the TEAC in UDMA33 (PIO4 UDMA2) mode. Is there a problem when two units on the same IDE cable have different UDMA modes? I’m asking this because for some reason the dvd writer doesn’t behave correctly when both drives are connected to the same cable.