A+ Certification, awarded by CompTIA® organization is the most widely recognized certification in the area of PC hardware and software technologies. To attain A+ certification, one need to pass 2 exams, namely A+ Essentials and one of A+ IT Technician, or A+ Remote Support Technician, or A+ Depot Technician exams. Given below is a quick review of notes for candidates preparing for A+ Essentials exam.
1)ECP (Extended Capability Port) is a joint effort by Microsoft and HP. It has less control overhead and best suited for transferring large chunks of data, such as between the computer and laser printer.
Ensure proper cable connection after replacing floppy disk drive. Some points to remember when you replace a FDD,
1. Check to see if the cable polarity / orientation is OK
2. Check whether the cable is properly seated and not loose.
3. Don't force the cable, that it may result in damage to pins
Interface cables used:
- floppy-34 pin,
- IDE-40 pin,
- SCSI-50 pin,
- SCSI Ultra wide-68 pin
2)If you encrypt a folder on an NTFS volume, all files and subfolder created in the encrypted folder are automatically encrypted. Therefore, it is recommended that you use encryption at the parent folder level.
Also note that you can't encrypt a file or folder that is compressed. If you want to encrypt a file or folder that is compressed, you need to first decompress the file or folder and then encrypt. Only NTFS volumes support file or folder encryption.
Monitors accumulate very high static charges and need to be handled very carefully. Before attempting any repair, it is imperative to discharge any accumulated charges on the monitor. You can use a jumper, one end of which is grounded, and touch the other end of the jumper wire to the anode of the monitor. While doing so, ensure that you are not in direct contact with the jumper wire or the anode. You can use a screw driver or a nose pliers with rubber handle for this purpose. A "POP" sound can be heard when the static charges accumulated on the anode lead getting grounded through the jumper wire. Remember, that if you get in contact with the static charge, it may lead to severe burns or even fatal accident!
Never wear a wrist strap when working on monitors. Monitors contain very high voltages, sometimes fatal to human, even when the power is turned off. If you are wearing wrist strap, the human body work as a conduit to discharge the electric charge.
The following devices require periodic cleaning:
1. Floppy drives
2. Tape drives
User level security gives better control of resource on user to user basis. Share level security assigns passwords to the resources rather than the users and less secure.
3)When signals are transmitted over a long distance, there will be ohmic losses, which result in loosing the strength of the signals. This is known as attenuation. Amplification is opposite of attenuation.
4)While preparing for dual boot with Windows 2000 Professional, note the following points:
1. Windows 2000 must be installed on a separate volume. If a separate volume is not available, repartition the hard disk suitably, and reformat. You also need to take suitable backup.
2. If you want to have dual boot between Windows NT 4 and Windows 2000 as the only operating systems, ensure that Service Pack 4 is installed on Windows NT 4. This is required since Windows 2000 upgrades the NTFS to NTFS 5. NT4 requires Service Pack 4 to read and write to NTFS 5.
3. You must install Windows 2000 only after installing MS-DOS or Windows 95.
.COM, .EXE, .BAT files are executable files.
+5 and +12 volts are the DC voltages commonly found on PCs
80386/486 operate at +5v
Pentium and above operate at +3.3v
Power supply wires - yellow=+12v, blue=-12v, red=+5v, & white=-5v
= 1024 bytes
1 MB = (1024 X 1024) bytes
= (1024X 1 KB) bytes
= 1,048,576 bytes
1 GB = (1024 X 1024 X 1024 )bytes
= (1024 X 1 MB) bytes
= (1024 X 1024 X 1 KB) bytes
= 1,073,741,824 bytes
KB stands for Kilobyte
MB stands for Megabyte
GB stands for Gigabyte
Byte is represented by "B" as in MB
Bit is represented by "b" as in kbps
One byte is 8 bits
1. A boot sector virus stays resident by infecting the boot sector of the computer
2. A Master boot record (MBR) virus infect the first physical sector of all affected disks
3. File viruses either replace or attach themselves to executable files, is the most commonly found virus.
4. Macro virus attaches itself to documents in the form of macros.
5. Memory viruses are viruses that execute and stay resident in memory. Trojan Horse is an example of memory virus.
10BaseT Ethernet complies with IEEE standard 802.3 and requires an RJ-45 connector to connect to the NIC.
10Base2 network, also known as Thin-net, uses BNC connector to connect to the NIC.
A 10BaseT cable can extend up to 100 meters without the use of a repeater
10Base2 network uses thin coaxial cable and need to be terminated with a 50 ohm termination at both the ends.
6)144-pin small outline DIMM (SO DIMM) is commonly used in notebook computers. 144-pin micro-DIMM is still smaller than the so-DIMM and used in sub-notebook computers. 72-pin SODIMM was used in older laptops.
256MB PCI Express is recommended for computers that use high-end video applications.
802.11b operates at 2.4 GHz, while 802.11a operates at 5 GHz. Typical data rate for 802.11b is 11 Mbps where as it is 54mbps for 802.11a.
802.11b is compatible with 802.11g. 802.11a is not compatible with 802.11b or 802.11g. Bluetooth is entirely a different protocol standard, and is not compatible with any of the 802.11 standards.
A CD can be recovered from any minor scratches by using polishing chemicals. But it does not guarantee repair. Only way to safeguard is to make a back-up copy of the CD.
7)A computer may reboot because the CPU is overheating. Ensure that you have sufficient ventilation for proper airflow, and that the CPU fan is working.
A connection device that is plugged into a computer's serial/parallel port in order to perform a loopback test is known as a loopback adapter.
A Flat blade screw driver has Minus slot
A Philips screw driver has X shape slot
A Torx screw driver has star tip or head
A Hex screw driver has hex head
A good fuse will show close to zero ohms ( typically less than 1 ohm). A bad fuse, will have open contact, and will show open
A hard disk should never be low level formatted at the customer premises. It is highly recommended that it is done at the manufacturer's or at any authorized center.
It is very cumbersome to change the partition sizes, once the hard disk is partitioned and used. It may require backing up all the data and restoring after repartitioning.
8)A work station/PC very commonly connects to a LAN by means of an RJ-45 connector on a LAN card (Also known as NIC, or Network Interface Card).
A hub is used as a concentration point for connecting together all the segments in a 10BaseT network. Another network devices that is used extensively for this purpose is a switch.
NIC (Network Interface Card) resides inside the PC cabinet.
A repeater is used for joining two or more Ethernet segments. A repeater can extend the distance over which the signal can travel without loosing out due to attenuation.
50 Ohm termination is normally used at the ends of a 10Base2 network to prevent signal reflection at the ends of the cable.
A Network Interface Card is required to be present in the PC to communicate over a LAN. A switch or a Hub may be required or may not be required depending on the network configuration. For example, if you have 10Base2 (Thinnet) network, you may not need a Hub or a Switch. Router is required only when there is routing involved.
9)A router for Internet sharing is normally configured using web browser. High-end routers may provide option for terminal connectivity, wherein you can connect a terminal, and issue commands for configuring the router.
A Secure Digital (SD) card is a small memory card used to make storage portable among various devices, such as cellular phones, PDAs, digital cameras, music players, and personal computers. It uses flash memory to provide nonvolatile storage, which means that a power source is not required to retain stored data.
A SIMM has a single row of 72 contact fingers, each making contact on both sides. An older version of SIMM card contain 30pins, and were used in 386 and 486 machines.
A DIMM (Dual-Inline Memory Module) has two rows of connecting fingers, one row on each side, and the total number of contacts are 168.
10)A. SCANDISK: ScanDisk is a utility program that was added to DOS Version 6.0. SCANDISK is a better compared to CHKDSK. SCANDISK can fix errors on data storage devices such as hard disks, floppy disks, RAM drives etc, and DoubleSpace compressed drives. It analyzes and repairs damage to the following:
1. Physical clusters
2. File allocation table (FAT)
3. Lost clusters
4. Cross-linked files
5. Directory tree
6. MS-DOS Boot sector
7. DBLSPACE volume header, file structure, compression structure.
B. CHKDSK (Check Disk): CHKDSK command, one of DOS commands, examines your hard drive for error conditions and reports the total size of the disk, how many files are stored there, and the space remaining. CHKDSK also reports the total amount of conventional memory in your system and the amount of conventional memory available. Note that CHKDSK can't report extended memory.
C. DFRAG: The DFRAG.EXE is included with DOS6.0 and later. DEFRAG utility arranges the clusters of data on the hard drive to achieve better performance by placing all of the clusters for a given file together in a contiguous order. DEFRAG does not do any repair on your disk, and errors, if any will remain on the disk.
D. BACKUP: DOS has a backup utility since version 2.0.
11)Active link LED on a network card is an indication that the link is up. You will be able to ping the local host even without the network connectivity. Device Manager NIC status not necessarily ensures that the network cable is plugged properly in to the NIC.
Active listening focuses on who you are listening to, in order to understand what he is saying. As the listener, you should then be able to repeat in your own words what they have said effectively. This does not mean you agree with, but rather understand, what they are saying.
AMR slot: AMR stands for Audio Modem Riser. AMR is a riser card that supports sound or modem function. With increasing CPU computational power, the digital processing job can be implemented in main chipset and share CPU power.
CMR slot: CNR stands for Communication Network Riser. CNR is a riser card specification that supports V.90 analog modem, multi-channel audio, phone-line based networking, and 10/100 Ethernet based networking. The digital processing is implemented in main chipset and share CPU power.
A modem can also be inserted using PCI slot. But, in such case, it will not be using onboard audio CODEC or CNR digital controller. The AMR card primarily attends to conversion of analog signals to digital and visa versa. Slot I is associated with CPU slots.
An IP address is considered private if the IP number falls within one of the IP address ranges reserved for private uses by Internet standards groups. These private IP address ranges exist:
10.0.0.0 through 10.255.255.255
172.16.0.0 through 172.31.255.255
192.168.0.0 through 192.168.255.255
Private IP addresses are typically used on local networks including home, school and business LANs including airports and hotels.
12)An UPS is desired to be purchased for any critical and un-interrupted use of computers. It has the following benefits:
1. Provide protection against small surges
2. Filters noise from entering the computer
3. Provide power to the computer during line power failure
4. Give stable power to computer, even when the line power is unstable.
Note that the UPS can give un-interrupted power only for a fixed amount of time under a given load, in the absence of line voltage.
Anti-virus software, and anti spy-ware software can be used to clear malicious programs from a computer. Also, note that you need to install up-to-date Service Packs, and patches.
Anti-virus update files are traditionally called as "Definitions".
If a PC becomes slow, as a first step, you need to run Disk Cleanup and Disk Defragmenter. Additionally, you can consider adding a second hard drive or more memory.
13)As the humidity decreases, static build up will increase and vice versa. A level of 50% is considered safe. Below 50% humidity, static build up will be more.
Asynchronous serial communication uses Start-bit/Data-bits/Stop-bit. A modem connecting to the Internet is a typical asynchronous device.
Synchronous communication uses clock signals to transfer information. Does not use start/stop bits. Synchronous communication is normally used for high speed data transfers.
Batteries contain environmentally hazardous chemicals and therefore, should not be disposed through dust bit. Always refer to the manufacturer's instructions or the relevant State guidelines. The same is true when you are disposing chemical solvents.
Automated System Recovery (ARS) requires that a system backup be taken using Windows XP Backup utility.
14)AT motherboards were discontinued in the mid 1990s. The AT motherboard can be distinguished by the position of key board plug and power socket. Also, it has only a key board connector on board and doesn't support other ports for mouse or printer. Baby AT is a form of AT motherboard with reduced dimensions. AT motherboard is also called Full AT. ATX mother boards have serial and parallel ports to support printer, mouse and also USB support is provided. ATX has one rear plate that enables acess to all necessary ports. Also, ATX uses one P1 power connector instead of P8 and P9 connectors. The one shown in the exhibit is an ATX motherboard.
ATX power supply provides three different voltages: 3.3Volts, 5Volts, and 12Volts.