• Computer glossary - U

    by
    computerguru
    Published on 02-03-2010 07:03 PM

    UDF (Universal Data Format) — a file system used by modern CD-RW drives.

    UDMA (Ultra-DMA) — an ultra-direct access to the memory. The range of fast-operating modes of data exchange with hard disks providing speed from 33 to 133 Bbyte/sec.

    UDP (User Datagram Protocol) — users’ datagram protocol. One of the two principal Internet protocols (together with TCP), does not ensure a bundle delivery, but provides a faster data transfer.

    UEI (Update Interrupt Enable) — one of the three bits controlling the interrupt IRQ8 = INT 70h from system watch (RTC). The UIE bit enables interrupt while system time updating, i.e. once a second.

    UHCI (Universal Host Controller Interface) — a universal main interface controller. A type of main controller of the USB 1.x Bus.

    UMA (Upper Memory Area) — address space area of a real mode as large as 384 Kbytes, reserved for ROM BIOS. The RAM memory can be reflected on the spare UMA spaces by means of memory managers. It can be used for download of drivers and resident programs thus freeing the main memory.

    UMB (Upper Memory Block) — uninterrupted UMA part, not used for ROM BIOS the RAM memory is reflected onto by means of memory managers.

    UMC (United Microelectronics Corporation) — the leading integrated microcircuit manufacturer.

    URL (Uniform Resource Locator) — the Internet addressing system.

    USB (Universal Serial Bus) — a universal serial bus. Interface for various peripheric devices connection. Supports hot connection/disconnection and power supply from the bus. Operates on speeds as high as 1.5 Mbit/sec, 12 Mbit/sec and 480 Mbit/sec (the latter is for the version 2.0)

    UTP (Unshielded Twisted Pair) — a cable type widely spread in local networks.