When setting up a Device Data transfer it usually goes:

Setup DMA Controller
Setup Device
... ^-Tell Device to start

I have a working SB Driver that follows this for the 8237 DMA Controller and SB16 however the pattern doesn't do anything when working with ATA Hard Drive controllers.

my present code uses PIO as patch work to ensure the overall code works however there is so much overhead involved in waiting for the disk heads to reach their destination (nevermind the actual transfer) that the driver I'm working on can't be considered complete until the DMA code is applied.

Does anyone know how to tell the ATA Controller it should use DMA?

Thanks