what's a dma
Direct Memory Access (DMA) Direct memory access (DMA) is a method that allows an input/output (I/O) device to send or receive data directly to or from the main memory, bypassing the CPU to speed up memory operations. The process is managed by a chip known as a DMA controller (DMAC). In older computers, four DMA channels were numbered 0, 1, 2 and 3.