46 terms

introduction to computer

a hard disk drive or HDD, is always given a letter. Sometimes this drive/letter combination is called a volume
the division of a hard disk drive
file allocation table (FAT)
the FAT keeps track of files and directories
another type of allocation system created specifically for Windows Nt
master file table (MFT)
the MFT deeps track of where all the files are located on the disk, and it also contains all the extra small files Windows creates within the table itself
system partition
will contain the entire OS and all your applications. The actual size of this partition depends upon how many apps you load and their size. The second partition, whichcan be any size, is reserved for all your data files, music and movies, and downloads
when a hard drive is partitioned it is subdivided into smaller sections called sectors
contiguous sectors
a sector can only hold so much memory (4kb) before it is split into contiguous sectors
when a file is split apart across a drive it is said to be fragmented
when your system puts all the fragmented files together to make looking up files faster
the NTFS file system has an added security feature. An encrypted file cant be opened or changed by anyone except those logged-in users with proper permissions
parallel scan
one of two common techniques used in tape recording (back-ups). It records data on tracks that are parallel to the edge of the tape
longitudal scan
another technique for backing up files. A stationary recording head is held perpendicular to the tape as it is pulled past
helical scan
a rotating head is used to record the tracks at an angle to the tape as it is pulled past. This results in grater relative speed between the recording head and the tape
quarter inch cartridge (QIC)
one of the older backup technologies.the original cartridge was the size of todays VHS tapes
the original travan cartridge had a 400MB capacity. The travan is backward compatible with older QIC tape formats
digital audio tape (DAT)
a popular tape backup format in use today. Orginally designed by sony for recording audio, this technology was quickly converted to computer use
super digital linear tape (SDLT)
these drives are generally larger and more expensive than their DAT counterpart. However, they can store an enomous amount of data, hundreds of gigabytes, and they are especially popular with minicomputers and mainframes.
full backup
the full backup records every file that is to be backed up. It takes the longest to record because every file is copied. It also requires the greatest storage capacity for the same reason. However, it requires the shortest time to restore because everything is on a single tape
incremental backup
it shortens the record time by backing up only those files that have changed since the last full or incremental backup. The restoration process can take a long time and may involve several tapes
differential backup
a good compromise between the full and incremental backup. It records only those files that have changed since the last full backup. Therefore, it takes less time to record than a full backup, although more than an incremental backup
devise driver
the driver can be thought of as an interpreter from hardware to windows and vice versa
microsofts windows hardware quality labs (WHQL)
manufacturers could submit a driver to WHQL for testing and evaluation
signed drivers
a driver with a digital signature representing that it has been checked and tested by microsoft
programs that exploit or take advantage of previously unknown OS or application bugs
a fix or patch in a previously unknown hole in windows
windows update
a system that keeps track of the updates that are already installed and regularly checks for new updates that may be available
virtual memory
a technique used by the OS to take advantage of extra hard drive space. A sort of hard drive extension for your RAM
paging file
windows typically sets aside a portion of your hard drive for the paging file, which is the actual file that contains virtual memory
system restoration
a process that involves a CD or two or a special hidden partition on the hard drive that is used to get your computer system back to the first day condition
restore point
a saved point in your system in which the running condition is good
safe mode
found in the startup menu. This mode will allow you to uninstall devices and applications, and perform basic surgery on the system
last known good configuration
this option launches windows with the registry settings that were used the last time windows launched properly
the profile includes everything on your desktop, any GUI personalizations, and network settings, and everything in you're my documents folder
files and settings transfer wizard
a tool used for making a backup of your profile in which you can reload the OS, copy that saved profile back in, and it will look like nothing has changed at all
disk image
an exact duplicate of your drive used if the system gets corrupted
universal serial bus (USB)
it brings plug and play to the peripheral world. A single USB channel can handle up to 127 devices. USB allows for hot pluggable peripherals
a problem with parallel cables where all 8 bits are transmitted at the same instant, they may not be received simultaneously
a problem with parallel cables where the waveform tends to overshoot as the logic levels change between 1 and 0
interrupt request (IRQ)
used to refer to either the act of interrupting the bus lines used to signal an interrupt, or the interrupt input lines on a Programmable Interrupt Controller (PIC). The interrupt request level (IRQL) is the priority of an interrupt request
institute of electrical and electronics engineers (IEEE-1394)
a serial bus interface standard for high-speed communications and isochronous real-time data transfer, frequently used by personal computers, as well as in digital audio, digital video, automotive, and aeronautics applications
sampling frequency
is the number of times per second the analog signal is sampled as it is converted
analog to digital converter (ADC)
a device that looks at the sine wave at periodic intervals, which are set by the sampling frequency. The ADC checks the amplitude fo the signal and assigns that level a binary value, then checks it again
pulse code modulation
the result of ADC
dynamic range
the difference between the highest and lowest sound levels in sampling
lossy compression
one of two ways to compress data which involves an aggressive process(algorithm) that actually throws away bits of data