The Mesa 7I43 is a low-cost, general-purpose programmable I/O card thatconnects to the host computer via a USB or PC parallel port. The board uses a 400,000 gate Xilinx Spartan-3 FPGA for all logic tasks. Efficient switching regulators are used for the FPGA core and 3.3V power, allowing the 7I43 to be USB bus-powered. It can also be powered by an external 5V source. The board has 48 I/O bits available on two 50-pin connectors. Both connectors use I/O-module rack-compatible pin-outs. All I/O bits are 5V-tolerant. Configurations are provided for simple GPIO, host-based motion control, buffered step/direction generation and waveform generation.