AT family of 6U VME 64x bus compatible Single Board Computers (SBC) are based on PowerPC processors from IBM. The SBC is fully compliant to ANSI/VITA 1.1-1997 VME64x standard. The AT-VME-SBC is a rugged single slot SBC powered by IBMs PowerPC 750CXe low power, high performance processor series, featuring state of the-art Reduced Instruction Set Computer (RISC) architecture. It offers superior computing power providing up to 256 KB of L2 cache1, up to 600 MHz of clock speed2, up to 512 MB of SDRAM with ECC Protection, 8 MB of Boot Flash, 32 MB of User Flash and 32 KB of NVRAM. There is also an option for providing 128 MB of High-Density Flash File for mass storage purposes. The AT-VME-SBC has its internal architecture based on two separate PCI buses, one operating at 66MHz and the other at 33MHz, allowing the separation of the slower PCI devices from the faster ones. This enables each of the PCI devices to operate at their maximum speeds. In addition to the high performance processor architecture, the SBC provides multi-protocol interfaces in the form of two dual redundant MIL-STD-1553B channels (available optionally), two high-speed synchronous serial ports, four standard UART serial ports and 16 digital I/O channels. The SBC also features a watchdog timer, Real Time Clock and comes equipped with one PMC module site.