NEC3500A Coaster Maker - Need Help



My burner was working fine for months (burning at 16X speed) and then my little sister came to visit. Not sure if she did something or I did it, but now it makes coasters or burns weird. Symptoms:

  • When it does burn, the buffer will max out and then get drained quickly, max out again, then drain. Max speed it tops out at is 2.3X burning (on a 16X burner).
  • When it does not burn, the buffer will pulse like above, but will fail somewhere in the middle (not at the same point in time for each burn).

Any suggestions on how to diagnose the problem? I didn’t see a sticky on common things to do to figure out what’s causing problems.


sounds like a dma problem see this guide also check dma settings in bios make sure its all set to auto


Nope, double checked to make sure DMA is enabled and it is. Any other ideas?


My bad, it actually was something to do with the DMA setting. It was turned on but for some reason it was running in PIO mode anyway (finally noticed that fact after looking at it for the sixth time). I checked the bios and the settings in device manager and it should’ve been on. So I deleted the 2ndary IDE channel and when it was reinstalled it worked. Thanks for the help.

As a suggestion, please add symptoms of DMA issues to a sticky somewhere…

Thanks again!