| * not in alphabetical order, to
find a term goto "FIND on this page in menu bar" |
| NVRam
Non-volatile random-access memory
|
| Ram is
integrated-circuit (lC)
memory whose contents can both be read and overwritten as required; it
forms the 'main memory' of most microcomputer systems. Normally, Ram is
'volatile': that is, it loses its contents when the power to the
computer is switched off (hence the need to save your work to disk).
NVRam is able to retain its contents thanks to a battery that
automatically takes over when power is lost. |
| EEPROM
electrically erasable
programmable read-only memory |
The
DCI component works in conjunction with the GDI to speed up display
on your CRT. It was recendy supplanted by DDI.
A
special type of read-only memory (ROM) that can be erased and written
electrically. EEPROM is frequently used for system-board BIOSes so that
a computer's BIOS can be updated just like a piece of
software. See
also ROM, EPROM, and BIOS. |
| OTP
Eprom One-time
programmable erasable
programmable read-only memory |
| The
Eprom memory chip is made to be programmed, erased and
reused.
Erasure is achieved by shining highintensity ultra-violet
light
through a window in the ceramic body of the chip. The
OTP
version has no window, so it can't be erased and re-used. |
| EMS
Expanded
Memory
Specification |
| A
bankswitched memory management scheme developed by
Intel, Lotus, and Microsoft that allows MS-DOS applications
(normally
limited to 640K of memory) to access vast quantities of memory. The
first widely accepted version of the EMS specification, Version 3.2,
supported up to 8MB of memory, and Version 4.0
increased the limit to
32MB. Memory that conforms to this standard is often referred
to as
expanded memory. EMS memory has been all but made obsolete by
protected-mode operating systems such as Window |
| DMA
direct memory access |
| A
technique that some
hardware devices use to transfer data to or from memory directly
without requiring the involvement of the CPU. |
| DRAM
dynamic random access memory |
| The
readable/writable memory used to store data in personal
computers. DRAM stores each bit of information in a
"cell" composed
of a capacitor and a transistor. Because the capacitor in a DRAM cell
can hold a charge for only a few milliseconds, DRAM must be continually
refreshed in order to retain its data. |
| EDO
RAM extended data-out random access
memory |
| A
form of DRAM that speeds accesses to consecutive locations in memory by
(1) assuming that the next memory access will target an address in the
same transistor row as the previous one and (2) latching data at the
output of the chip so it can be read even as the inputs are being
changed for the next memory location. EDO RAM reduces memory
access
times by an average of about 10 percent compared with standard DRAM
chips and costs only a little more to manufacture. |
EDRAM
enhanced
dynamic random access
memory
|
| A
form of DRAM that boosts
performance by placing a small complement of static
RAM (SRAM) in
each DRAM chip and using the SRAM as a cache. Also known as cached
DRAM, or CDRAM |
Hardware
-
Storage
| Logical Drives |
There
are 2 ways to view the disk drives in your microcomputer system, either
logically or physically. When you view a drive physically,
you are
looking at how many tangible drives your system can access.
These
physical drives may be logically subdivided to produce logical
drives during the disk parcloning process. Physical
drives
are referred to by number while logical drives are referred
to by
letter. You could have three logical drives
with C
and E residing on physical drive 1 and drive D residing on
physical
drive 2. You could also have other logical drives such as RAM
Disks or
remote
disks in a network. |
| Lost Allocation Units |
| Portions
of a file (or files) have become detached from the rest of the
file or that a file has become separated from its directory
entry |
| CRC
cyclical redundancy check |
A
mathematical method that permits errors in long runs of data
to be
detected with a very high degree of accuracy. Before data
is transmitted over a phone, for example, the sender can
computer
a 32-bit
CRC value from the data's contents. If the receiver
computes a
different CRC value, then the data was corrupted during transmission.
Matching CRC values confirm with near certainty that
the
data
was
transmitted
intact |
| FAT
File
Allocation Table |
| The
file system used by DOS
and 16-bit versions of Windows to manage files stored on hard
disks,
floppy disks, and other disk media. The file system takes its name from
an on-disk data structure known as the file allocation table,
which
records where individual portions of each file are located on the
disk. |
| Mag Tape |
| Mag
tape is
an abbreviation for the various kinds of magnetic
recording tape used to store computer programs and data. The tapes are
used to store info off-line as backups. Microcomputers
equipped with
tape backup systems use magnetic tape contained in cartridges or
cassettes of many sizes. The data that is stored and
retrieved from mag
tapes is done in a sequential fashion. That is, reading or
writing a
specific item on the tape requires reading everything in front of it |
| FTP
File Transfer Protocol |
A
set of rules that allows two
computers to talk to each other as a file transfer is carried
out This
is the protocol used when you download a file to your computer
from
another computer on the Internet.
GO! (Graphics Device Interface) The component of Windows that permits
applications to draw |
Megabyte
Mega'
is a
binary analogue to the decimal unit "million".
|
One
megabyte is exactly
1,048,576 bytes
1024 times 1024 or
2 to the 20th power
The capacity of a hard disk drive for a personal
computer is
measured in Megabytes, a 20 Mb drive, a 40 Mb drive, a 500 Mb drive
etc. |
|
