The National Instruments PXI-8221 is a dual-slot PC Card Carrier designed for use within a single-slot PXI module, offering versatile connectivity options for both PXI and CompactPCI systems. This carrier enables users to incorporate any functionality supported by PCMCIA modules, accepting CardBus-type cards and accommodating a combination of two type I or type II PC Cards or one type III PC Card. The PXI-8221 supports 16-bit PCMCIA PC Cards and 32-bit CardBus PC Cards, operating at the full PCI bus speed of 132 Mbytes/s. A key feature of the PXI-8221 is its implementation of Serialized IRQ, which bridges legacy ISA interrupt requests in a PCI architecture, thereby facilitating effective communication between ISA components and PCI controllers. The module includes dual LED status indicators for confirming proper card insertion and configuration, and it automatically provides the necessary power for 3.3V or 5V PC Cards. Although the PXI-8221 has been designated as obsolete by National Instruments, it remains available for purchase and repair through Apex Waves. The PXI-8221 is compatible with a range of controllers, including PXI-8110, PXI-8108, PXI-8102, and PXI-8101, and comes with a 2-3 year warranty, along with user and maintenance manuals available for download. For pricing information, please contact a sales representative.