Basic PC Anatomy
History of the QWERTY Keyboard
In the late 1860s, American inventor Christopher Scholes developed the first typewriter. The keys were originally laid out in alphabetical order, but this led to problems with the type bars jamming when typing at speed. To remedy this, Scholes relocated the keys to keep the most frequently used letters apart, resulting in the QWERTY keyboard. More ...
Hardware Resources Explained
Hardware devices, such as modems, network circuits, sound circuits, and so on,
require system resources such as Interrupt Request (IRQ) lines, Input/Output Port (I/O) addresses, Direct
Memory Access Channels (DMA), and a range of Memory Addresses for storing code and data. Each device needs
its own set of resources. If two devices attempt to use the same resource, your system may lock up or crash. More ...
The Computers Back Connector Panel
So although the computer's back panel appears to be a complicated mess, each connector has a specific shape, number and pins, and polarity key that allows only the proper cable to be plugged in. If you get a nice comfortable feeling like your not smashing pins when you plug a cable in, then you can feel secure that nothing will blow up. More ...
The Hard Disk Drive vs. The Solid State Disk
Much has been written about solid state disks (SSDs) becoming the next big thing1 in the
IT industry. But as to whether or not we have enough knowledge of how it will revolutionize
the industry is a different question. How much do we really know about SSDs? More ...
How Hard Disks Work
A hard disk drive consists of several main components. The first is one or more thin disks
that spin at anything from 3650 to 15000 RPM. The second major component is the head assembly
which consists of record/playback heads mounted on arms which pivot so that the heads can
be placed over any of the tracks. More ...
How a laser Printer Works
Laser printers work by using a laser beam to transfer an image to an electrically charged,
photo-sensitive drum. The charge on the drum attracts toner ink, which is transferred
to the paper. The primary steps in the laser printing process are listed below. More ...
The Master Boot Record (MBR)
The Master Boot Record, created when you create the first partition on the hard disk,
is probably the most important data structure on the disk. It is the first sector on
every disk. The location is always track (cylinder) 0, side (head) 0, and sector 1. More ...
What is USB OTG?
USB is wonderful because it allows you to connect and disconnect devices from the computer without rebooting the computer. However, wouldn't it be even more wonderful if two USB devices, like a digital camera and a storage device could connect to each other directly? That's what USB On-The-Go (OTG) does. More ...
How Does the CPU Cache Work?
CPU's however use a 2 level cache system. The principles are the same. The level 1
cache is the fastest and smallest memory, level 2 cache is larger and slightly slower
but still smaller and faster than the main memory. More ...
PC Sound Circuitry
Actual physical sound is an analog phenomenon while the computer is digital. To output a sound stored on a computer disk to a speaker the sound circuit uses a digital-to-analog converter. Sound input to the computer for recording uses an analog-to-digital converter. So PC sound circuitry is primarily an AD/DA-converter or a "coder/decoder", usually shortened to "codec". More ...
What You Need To Know About Server Memory
DDR is Double Data Rate which is what all memory is now. Since DDR came out it's gone through a few generations DDR, DDR2, DDR3 and now DDR4. These different generations of memory have different peak transfer rates. More ...
PC Technician Street Smarts: A Real World Guide to CompTIA A+ Skills
Hit the ground running with the street-smart training you'll find in this practical
book. Using a "year in the life" approach, it gives you an inside look at the common
responsibilities of PC Technicians, with key information organized around the actual
day-to-day tasks, scenarios, and challenges you'll face in the field. More ...