DMA transfer RAM-to-RAM

Question

A friend of mine has told me that on x86 architecture DMA controller can\'t transfer between two different RAM locations. It can only transfer between RAM and peripheral (such a

Answer 1

ISA (remember? ;-) DMA chips certainly have a Fetch-and-Deposit transfer type.

However, from the MASM32 forums:

Hi,

Checking in "The Undocumented PC", he says memory to memory DMA is possible. He then goes on to say that there can be problems, limitations, and that the CPU can do the copy faster than the DMA hardware anyway (MOVSD on 386+).

So it seems to be a yes you can, but who cares, kind of thing.

Regards,

Steve N.