The high-density 12AI64 board provides cost effective 1,500,000 conversions-per-second 12-bit analog input capability in a single width PMC format. The inputs are configurable either as 64 single-ended channels or as 32 differential channels,and the input range can be software selectable as 10V, 5V or 2.5V. Scan rates can be controlled from either (a) an internal rate generator, (b) through an external digital input, or (c) by direct software commands. Multiple 12AI64 boards can be connected together for synchronous scanning. Data buffering is accomplished through a 64K sample FIFO. Internal auto calibration networks permit calibration to be performed without removing the board from the system.