The National Instruments part number 779808-01 refers to the USB-6221 Multifunction I/O Device, designed to provide versatile data acquisition and control capabilities. This device is equipped with 8 differential analog input channels and features a total of 2 analog output channels, along with 24 digital I/O lines. Both the analog input and output capabilities can sample data at rates up to 250 kS/s, making it ideal for demanding applications such as manufacturing tests, laboratory automation, design testing, and research. The USB-6221 supports high-voltage measurements when paired with compatible signal conditioning accessories, including SCC and SCXI. Its digital I/O lines facilitate pulse-width modulation, enabling the control of various devices such as lamps, pumps, valves, fans, and motors, with a driving capacity of up to 24 mA. This device offers multiple I/O connectivity options, including a single 68-pin VHDCI connector for PCI/PXI configurations and variations with 64 screw terminals or 20 BNC connectors and 30 screw terminals for USB models. Additionally, it features an output FIFO with a capacity of 8,191 samples shared across the active channels. Data transfers are effectively managed via PCI/PXI DMA (scatter-gather), interrupts, programmed I/O, or USB Signal Stream for USB connections. The analog output supports both non-periodic waveforms and periodic waveform regeneration from the onboard FIFO or the host buffer, allowing for dynamic updates. While National Instruments has declared the 779808-01 obsolete, the device remains available for purchase and repair through Apex Waves.