Abstract: In a Local Area Network (LAN) system, an ethernet adapter exchanges data with a host through programmed I/O (PIO) and FIFO buffers. The receive PIO employs a DMA ring buffer backup so incoming packets can be copied directly into host memory when the PIO FIFO buffer is full. The adapter may be programmed to generate early receive interrupts when only a portion of a packet has been received from the network, so as to decrease latency. The adapter may also be programmed to generate a second early interrupt so that the copying of a large packet to the host may overlap reception of the packet end. The adapter may also be programmed to begin packet transmission before the packet is completely transferred from the host to the adapter, which further reduces latency.