Glossary of Acronyms

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UART - Universal Asynchronous Receiver/Transmitter. A built in chip on internal modems for serial communications. The UART performs the same function of the serial or COM port.  A chip device that controls the RS-232 serial port in a PC-compatible system. Originally developed by National Semi-conductor, several UART versions are in systems today. The 8250B is used in PC or XT class systems, and the 16450 and 16550A are used in AT class systems.

UMA - Upper Memory Area. The area of memory from 640 KB to 1024 KB where devices such as network and video cards are loaded. Device drivers such as HIMEM.SYS and EMM386.EXE used unused portions of Upper Memory and convert them to units called Upper Memory Blocks.

UMA - Uniform Memory Access. The traditional architecture of SMP (Symmetric Multiprocessing) used to support high end information processing. UMA makes all memory locations equally accessible to all processors. Today, nearly all multiprocessing servers are UMA configured SMP servers. UMA suffers from certain limitations. Most significantly, once a server includes more than 16 processors, application performance usually doesn't improve. The problem lies in the bandwidth of the interconnect between the processors and memory devices, where an information bottleneck develops.

USB - Universal Serial Bus. A new standard serial interconnect with up to 12 Mbps bandwidth for connecting PC's to keyboards, printers, and other peripheral devices starting to appear on PC motherboards. The USB may make parallel port and SCSI interface devices obsolete.

UPS - Uninterruptible Power Supply. Provides power to devices when the regular power supply fails. The UPS runs off of rechargeable batteries and can keep a server operating for up to 15 to 30 minutes after power failure, which is enough time to warn users still on the network that the server is coming down. Typically, when the UPS is inactive the batteries are constantly charging.

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Compiled by Scott McArdle, MagnaCom Limited. I hope this list has helped you and if there is an item that should be on this list, please let me know. Thanks. PS, I've spent 100's of hours maintaining this list, please don't be a LAMER.