Day 20

 

Input/output

Devices

 

In this lesson, we will look into the different devices, which the computer uses to function properly.

 

We will look at:

Input/output ports

Monitors

Keyboards

Pointing devices

&

Web cams

 

Input/output ports

 

Ports allow you to add devices to your computer.  Ports include: serial, parallel, video, mouse, keyboard, game, speaker, and USB.

 

Serial Ports

These ports send data in a sequential, one bit at a time manner.  This is older technology and is used in one- way communication, as found in a mouse or printer.  PCs have two serial ports called Com1 and Com2.  Transfer rates are around 110 to 115 KB per second.

Terms: Synchronous, asynchronous, Cyclic redundancy checking, 25 pin, and 9 pin.

 

Parallel ports

These are used to connect printers using a DB 25 female connector.  These also go by the name of LPT1.  These came out during the 1960s and allowed for data to be sent at 8 bits at a time.  Making them better for transferring data than serial ports.

Parallel port cables have a limit of 15 feet.

Newer standards for parallel ports allows for transfers of up to 2 Megs per second.

 Terms: IEEE, ECP, FIFO, EPP, and bi-directional.

 

Keyboard ports

Older AT style computers used a ½ “ diameter round DIN connector with five pins. ATX systems use a keyboard connector called PS/2 or “mini” DIN with 6 pins.  You can also use a USB  keyboards on newer systems. 

 

Mouse ports

Older Mouse designs used the serial port to connect with the PC. Newer designs use a mouse connector called PS/2 or “mini” DIN with 6 pins.  You can also use a USB  mouse on newer systems. 

 

Game ports

A game port is a DB15 female analog interface port .  It is used for joysticks, game pads, and flight controllers.  Two game ports can work on one system.  Newer systems can have these same devices on the USB port.

 

 USB

Universal Serial Bus is designed to replace all other ports. A system can have USB 127 devices.  USB advantages include:

No external power cords are needed

Hot PnP

Automates aspects of device initialization

Easy to install

 The OS loads the drivers when it sees the device

Works with Win95 OSR2 and later

 

Firewire

This is another high speed serial bus made for HDDs, CD-RWs, and video editing devices.

 

Video ports

VGA has a DB15 connector.  SVGA is now standard for today’s system. 

 

-Devices-

 

Monitors

 

Keyboards

 

Pointing devices

 

Review

 

Page 180 of Supporting PCs

 

Second hour

 

Sing in for attendance.

Anyone needing raffle tickets?

The 386 tower systems need to be completed.

Min. standards

Boots up reliably

4 to 8 Megs of RAM

A working HDD, with DOS

A working FDD

A working video card