Specifications

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Appendix A Glossary
block from 128 bytes to 1,024 bytes. YModem-
batch adds the capability to transmit batches, or
groups, of files without operator interruption.
YModemG is a variation that sends the entire file
before waiting for an acknowledgment. If the
receiving side detects an error midstream, the trans-
fer is aborted. YModemG is designed for use with
modems that have built-in error-correcting
capabilities.
Z-buffering A 3D graphics technique used to
determine which objects in a 3D scene will be visi-
ble to the user and which will be blocked by other
objects. Z-buffering displays only the visible pixels
in each object.
zero wait states See wait states.
ZIF (zero insertion force) Sockets that require
no force for the insertion of a chip carrier. Usually
accomplished through movable contacts, ZIF sock-
ets are used by 486, Pentium, Pentium Pro, and
other socketed processors (including the latest
Pentium 4 and AMD Athlon and Duron models).
ZIP (zigzag inline package) A DIP package
that has all leads on one edge in a zigzag pattern
and mounts in a vertical plane.
Zip drive An external drive manufactured by
Iomega that supports 100MB, 250MB, or 750MB
magnetic media on a 3 1/2" removable drive.
Zip file A file created using PKZIP, WinZip, or a
compatible archiving program.
zipping The process of creating a PKZIP- or
WinZip-compatible archive file. See also unzipping.
ZModem A file-transfer protocol commissioned
by Telnet and placed in the public domain. Like
YModem, it was designed by Chuck Forsberg and
developed as an extension to XModem to over-
come the inherent latency when using Send/
Ack-based protocols, such as XModem and
YModem. It is a streaming, sliding-window
protocol.
zoned recording One way to increase the
capacity of a hard drive is to format more sectors
on the outer cylinders than on the inner ones.
Zoned recording splits the cylinders into groups
called zones, with each successive zone having more
and more sectors per track, moving out from the
inner radius of the disk. All the cylinders in a
particular zone have the same number of sectors
per track.
zoomed video A direct video bus connection
between the PC-Card adapter and a mobile system’s
VGA controller, enabling high-speed video displays
for videoconferencing applications and MPEG
decoders.
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