User's Manual

Glossary
96 TuneUp Utilities 2006
most important staticians of the 20
th
century. Tukey had a particular talent for
coining terms, he also created the term “software”.
Byte
A byte is the smallest addressable unit of memory. It consists of eight bits. As a
bit can have one of two values, one byte allows 256 combinations (two to the
power of eight), and can therefore represent 256 different conditions or
characters.
Cache
A fast form of memory that temporarily stores data for rapid access. There are
different kinds of caches:
- Caches that store data from main memory in the immediate vicinity of the
CPU (L1/L2 cache).
- Caches that store data from the hard disk in the main memory (such as
Smartdrive or smartdrv.exe).
- Caches that store data from slow CD-ROM drives on the hard disk.
The hard disk cache stores write and read accesses in the disk hardware.
Depending on the model, a hard disk sold in 2000 has a cache between 128 and
4096 KB; EIDE disks frequently have a 512 KB cache, while SCSI disks often
have a 1024 KB cache. As the algorithms used vary in their effectiveness, a
larger cache does not necessarily make a disk faster. If the data in the cache is
needed again, the cache accelerates operations because the data does not have to
be read from the slower disk again.
ClearType
ClearType, introduced by Bill Gates at Comdex in Las Vegas in autumn 1998, is
designed to dramatically improve the readability of text on all screen types,
including simple screens. ClearType does not only use whole pixels for display,
but also uses invisible subpixels when calculating the display of the screen
contents. This technology can be used on desktop computers and PDAs (personal
digital assistants) or electronic books. Dick Brass, vice president of Technology
Development at Microsoft, claimed that ClearType makes economical screens
look like expensive ones, and makes expensive screens look like paper.
Clipboard
A special area in the main memory that is used by programs and operating
systems like Windows to temporarily store information so that it can be copied
or moved to other documents.
The terms in this glossary have been used with the kind permission from the
online dictionary “ARCHmatic-Glossar und -Lexikon” (www.glossar.de) by
Alfons Oebbeke and adapted by Carsten Scheibe.