BIOS Updates forum

American Megatrends BIOS, AMD K6 processor, GA-5aa mobo, 256MB RAM, Mitsumi writer CR 4802 TE.

Since formatting my hard drive I have had problems with buffer underruns. Previously it worked perfectly.

When it was 1st installed there was a problem of buffer underruns which was cured by the installer by going into BIOS setup and enabling DMA.

I have been into BIOS setup but cannot see where to make any changes. I tried enabling DMA through the device manager but each time I reboot it reverses the changes.

Can anyone help please?

Buffer underruns when? When copying from CD to CDRW?

DMA of HDD or CDROM/Writer is removed with next start ?
How old is your mainboard Bios ?
What's your OS ?
Tried to use ALI chipset drivers ?

The OS is Windows 98SE, and after I have enabled DMA for the CDROM/Writer through the device manager I have to re-boot for the changes to be effective. Windows warns me that the changes through device manager may not be supported by the mainboard. This appears to be the case, as when I return to device manager the boxes are unticked again. The BIOS must be about 5 years old now. That was when th PC was upgraded, and only the original drivers have been installed.

Sandra the diagnostic tool says that the BIOS is unflashable!

I feel it is something in the BIOS that causing the underuns because prior to the Format of the hard drive the writer copied disks, and made data disks at full speed no problem.

Thanks Dennis

Formatting the HDD is irrelevant to BIOS settings. You doubtless had better drivers installed before the format, or the burner software was configured differently. Your best bet is to get all the latest drivers and Win98 updates.

Your CD Burner seems new enough to be DMA capable. BIOS DMA (as in UDMA) is different than Windows DMA. What settings do you have your BIOS set to to detect your drives (Auto-Detect/Fixed)? Who is HD manufacturer and size?

The Windows message is generic...just a warning that the board and/or the device may not support DMA transfers...for those who like to fiddle and don't know what they may be doing. Better safe than sorry.

Underruns can be caused by many things...other programs running at the same time/etc...that interfere with the burning process. Hopefully you minimize that while burning. Also APM, ScreenSaver, and Virus protection can be causes of underruns...

The BIOS can't be 5 years old as you've mentioned. The Gigabyte GA-5AA is a fairly recent Super S7 board.
There's a very recent BIOS update at Gigabyte's website you might want to try.

I have managed to enable DMA to the drives via Device manager and that has completely solved the buffer underruns.

Thanks everybody>