What is DMAMask ?
DMAMask is used for two purposes :-
Standard Amiga devices can only use CHIP memory for DMA. Disk controllers are usually capable of using DMA to any memory.
The DMAMask value restricts DMA activity by a particular device driver to a particular area of memory.
The default value of 0xFFFFFF restricts DMA to the Zorro-II area. This is a bad idea for any Zorro-III based machine which always has memory outside this area. In this case 0xFFFFFFFF would be a better value.
The alignment can make a lot of difference to performance. Longword alignment is usually the best.
Follow this link for instructions on selecting the DMA Mask value
.