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Tuesday, July 14, 2020

In computing, what is a "bus"?

In computing, what is a "bus"?

  • Boolean Undulated Synchronization.
  • The part of the memory that processes data
  • A communication system that transfers data between components inside a computer or between computers
  • Binary Unified System

In computing, what is a "bus"?

EXPLANATION


Bus :-bidirectional universal switch
use to transfer data or power between computer components inside a computer or between computer.
point to point connection.

The bus contains multiple wires (signal lines) with addressing information describing the memory location of where the data is being sent or retrieved. Each wire in the bus carries a bit(s) of information, which means the more wires a bus has, the more information it can address. For example, a computer with a 32-bit address bus can address 4 GB of memory, and a computer with a 36-bit bus can address 64 GB of memory.

Types of computer buses

A bus is either a parallel or serial bus, and either an internal bus (local bus) or an external bus (expansion bus).
Internal bus vs. external bus

An internal bus enables the communication between internal components, such as a video card and memory. An external bus is capable of communicating with external components, such as a USB or SCSI device.
Parallel bus vs. serial bus


A computer bus can transmit its data using either a parallel or serial method of communication. With a parallel bus, data is transmitted several bits at a time. However, with a serial bus, the data is transferred one bit at a time.
Bus speeds

A computer or device's bus speed is measured in MHz, e.g., an FSB may operate at a frequency of 100 MHz. The throughput of a bus is measured in bits per second or megabytes per second.
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What is the maximum length specification for unshielded Cat6 cable when used in a 10GBASE-T environment?

What is the maximum length specification for unshielded Cat6 cable when used in a 10GBASE-T environment?

  • 328 ft (100m)
  • 100 ft (30M)
  • 180 ft (55m)
  • 365 ft (112m)

What is the maximum length specification for unshielded Cat6 cable when used in a 10GBASE-T environment?

EXPLANATION

Category 6 cable (Cat 6), is a standardized twisted pair cable for Ethernet and other network physical layers that is backward compatible with the Category 5/5e and Category 3 cable standards.

Cat 6 has to meet more stringent specifications for crosstalk and system noise than Cat 5 and Cat 5e. The cable standard specifies performance of up to 250 MHz, compared to 100 MHz for Cat 5 and Cat 5e.

Whereas Category 6 cable has a reduced maximum length of 55 meters when used for 10GBASE-T, Category 6A cable is characterized to 500 MHz and has improved alien crosstalk characteristics, allowing 10GBASE-T to be run for the same 100 meter maximum distance as previous Ethernet variants.
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From the old days of DOS, what does the "EMM" in EMM386 stand for?

From the old days of DOS, what does the "EMM" in EMM386 stand for?

  • Expanded Memory Manager
  • Enhanced Memory Module
  • Extended Memory Module
  • Executive Memory Mode
From the old days of DOS, what does the "EMM" in EMM386 stand for?

EXPLANATION

 EMM386 (software, storage)
An expanded memory manager for IBM PCs with an Intel 80386 or higher processor, part of MS-DOS version 5.00 or higher. EMM386 uses extended memory to simulate expanded memory and also provides upper memory blocks. It must be loaded by a DEVICE= command in your CONFIG.SYS file.

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Monday, July 13, 2020

In Linux system, which file contains the encrypted passwords of the users ?

In Linux system, which file contains the encrypted passwords of the users ?

  • /etc/crypttab
  • /etc/gshadow
  • /etc/shadow
  • /etc/password

 
In Linux system, which file contains the encrypted passwords of the users ?

EXPLANATION

In the Linux operating system, a shadow password file is a system file in which encrypted user password are stored so that they aren't available to people who try to break into the system.
Ordinarily, user information, including passwords, is kept in a system file called /etc/passwd.

SOURCE

http://searchsecurity.techtarget.com/definition/shadow-password-file
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Friday, July 10, 2020

In SQL Server, which of the following SQL queries will show the currently installed version of SQL?

In SQL Server, which of the following SQL queries will show the currently installed version of SQL?

  • Select version from @@version
  • @@version
  • Show @@version
  • Select @@version 


EXPLANATION

Variables starting @@ are system variables. You need a select to be able to return the value, so the answer is "Select @@version". The other three answers are nonsense, as far as SQL is concerned.

SOURCE

https://www.mssqltips.com/sqlservertip/1140/how-to-tell-what-sql-server-version-you-are-running/
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