Keyboard

The keyboard is one of the input devices are often used, with technology develops further on the PC keyboard is also increasingly developed. There are 4 types of keyboard is the most commonly used are:

1. Original PC or XT keyboard (83 keys) 
2. AT original keyboard (XT + Sysreq for OS / 2 + 10 function keys) 
3. 101-107 key PS / 2 keyboard (AT + function keys F11 and F12) 
4. 79 Keyboard, 82 keys for Notebook (Laptop)

The big difference between XT and AT keyboards are:

• put XT keyboard microprocessor inside the keyboard,
• AT keyboard, a microprocessor is assumed to be on the mainboard.

CD-ROM, DVD-R (RW) DRIVE

Speed ​​CD-ROM and CD-RW varied from 4X, 8X, 24X to 56X. At first CDROM data transfer speed of 150 Kb / s. So-speed 52X CD-ROM has the ability to transfer data 52 X 150 Kb / s = 7800Kb / s. Interface used is usually IDE (Integrated Drive Electronics). While the DVD-ROM drive is famous for his ability to read the disk format to 4.7 GB capacity than CD-ROM that only a maximum capacity of 720 MB.

Storage Media CD-R (Compact Disc Recordable) and CD-RW (Compact Disc Recordable and rewritable), capacity up to 100MB 720Mb, while DVD-R (Digital Versitile Disc-Recordable) and DVDRW 4.7 GB up to 17GB (double-sided, dual layer)