HISTORY OF DOS

HISTORY OF DOS

          The MS – DOS was developed in the years as shown below;

1981   :         MS-DOS 1.0 was released August 1981

1982   :         MS-DOS 1.25 was released August 1982

1983   :         MS-DOS 2.0 was released March 1983

1984   :         Microsoft introduces MS-DOS 3.0 for the IBM PC AT and MS-DOS 3.2             for N/w

1986   :         MS-DOS 3.2 was released April 1986

1987   :         MS-DOS 3.3 was released April 1987

1988   :         MS-DOS 4.0 was released July 1988

1991   :         MS-DOS 5.0 was released June 1991

1993   :         MS-DOS 6.0 was released August 1993

1994   :         MS-DOS 6.21 was released March 1994

1994   :         MS-DOS 6.22 was released April 1994

Keyboard: Keyboard is standard I/p device

There are three types of keyboards

1. Opto electronic type keyboard
2. Mechanical type keyboard
3. Membrane type keyboard

Types of keyboard based on connector

Normal Keyboard (5 pin connector keyboard)

1. Keyboard clock
2. Keyboard of data
3. Unused
4. Ground
5. + 5 V D.C

PS2 Keyboard

1. KB data
2. Unused
3. Ground
4. +5 V D.C
5. KB Clock
6. Unused

USB Keyboard or HID (Human Interface Device)

Types of keys based on keys

1. PC – XT (intended technology): It contains 83 keys
2. PC – AT (advance technology): It contains 84 keys
3. Cursor added keyboard or track ball keyboard: It contains 101 keys
4. Windows key added : It contains 104/105 keys
5. Power management added kb : It contains 108 keys
6. Multimedia or internet keyboard: It contains upto 125 to 130 last keys

Types of keys

1. Type writer or alphabetic keys (A to Z)
2. Numeric keys (0 to 9)
3. Control Keys (Ctrl, Alt, Esc, Enter)
4. Cursor movement key or arrow keys
5. Function keys F1 to F12
6. Toggle key (Caps lock, Num lock, Scroll lock)
7. Special characters keys (&, *, ( ), { })

Mouse

Communication mouse

There are two types of communication part

1. Serial
2. Parallel

Mouse is a pointing input device.

Types of mouse based on technology.

1. Mechanical mouse
2. Optical mouse or optic mouse
3. opto mechanical mouse

Type of Mouse based on Interface

1. Serial mouse
2. PS 2 mouse
3. Bus mouse
4. USB mouse
5. Wireless mouse

Type of Mouse based on Buttons

1. Single Button Mouse
2. Two Button Mouse
3. Three Button Mouse