أكاديميا - كولنز - معاجم الجيب العلمية - الكمبيوتر - انكليزي - فرنسي - عربي الحرف u

Academia - Collins - Pocket Scientific Dictionaries - Computer - English - French - Arabic The letter U

UHF
Abbreviation for ultra high frequency.

ULA

Abbreviation for uncommitted logic array

ultra high frequency (UHF)
ultra - high frequency f

Ultra high frequency is a specific range of radio waves with wavelengths ranging from approximately 10 to 100 cm. These waves are used for television transmission and as an output for a microcomputer connected via an antenna jack to display in a television receiver. Frequency values ​​are several hundred million hertz.

uncommitted logic array (ULA)
réseau m logique programmable

Programmable logic array. A name given to a chip that contains groups of logic circuits that have not yet been connected to each other.

1/2 cm

Place of connections with the chip

1/2 cm
Logic gate array

Each group is complete in itself but is not connected to the other groups and must be connected, by one or more connections. Thus, the chip maker makes the programmable logic array according to his standards, while the final layer (circuit pattern) is added according to the specifications desired by the buyer, which enables the latter to obtain a chip of a certain type without spending a lot on designing one of his own. See also ASICS.

underflow
dépassement m de capacité negative

Underflow. Generating a number, by division for example, that is too small to be stored by the computer (in fact, the computer stores zero as well). In floating-point notation, which uses two 8-bit words, this occurs when the resulting number is less than 39-10, that is, one over one followed by 39 zeros.

For example: dividing the number 0.00001 by 2, in a 6-bit calculator, gives zero. The missing digits on the right of the number are called null.

UNIVAC
UNIVAC. Abbreviation for UNIVersal Automatic Computer, the first commercial computer developed in 1951 by Remington Rand. Today it is called Sperry Univac.

UNIX
UNIX
UNIX. A new operating system developed by Bell Laboratories. The high-level language C was designed to be used with it.


update
mettre à jour

Update. A process of changing a file or software package to make it current. This process involves adding new data, making changes to previously saved data, and modifying the program to remove minor errors that have been found. This last process is sometimes called a patch.

For example, an update may be necessary for a payroll package due to new government legislation
regarding income taxes.

user group
groupe m d'utilisateurs

User group. A group of people who meet or correspond regularly because of their interest in a particular machine. Most microcomputers have their own user group, which is generally supported financially by the manufacturer but is supervised and managed by the members themselves. Meetings in these groups allow for sharing of problems and solutions and for providing information about new products. All members gain a great deal for a small cost.

user port
porte f de l'utilisateur

User port A socket with a socket behind it that allows the user to connect additional equipment to the computer. The port often - but not always - consists of eight data lines "out" and eight "in", in addition to certain voltage lines. The numbers sent are represented in binary code.

For example: the number 12 is represented using 8 bits on the eight lines 00001100, where the voltage of the logical 0 is 0 volts, and the voltage of the logical 1 is between 4.5 and 5 volts.

A serial port is where data is sent in series, one after the other. Examples of this are RS232C and RS423 ports. A parallel port is where data is sent in parallel. Each bit has its own wire, and all bits are sent simultaneously. An example of this is a centromics port.

utility programs
programmes mpl utilitaires

Utility programs . Programs designed to perform specific tasks, such as printing a file saved on magnetic tape onto a printer, or copying data from one disk to another before executing the program.