PC System Design Guide

The PC System Design Guide (also known as the PC 97, PC 98, PC 99, or PC 2001 specification) is a series of hardware design requirements and recommendations for IBM PC compatible personal computers, compiled by Microsoft and Intel Corporation during 1997–2001. They were aimed at helping manufacturers provide hardware that made the best use of the capabilities of the Microsoft Windows operating system, and to simplify setup and use of such computers.

Every part of a standard computer and the most common kinds of peripheral devices are defined with specific requirements. Systems and devices that meet the specification should be automatically recognized and configured by the operating system.

Versions
Four versions of the PC System Design Guide were released. Within each version, a distinction was made between the requirements of a Consumer PC, an Office PC and an Entertainment PC.

Version	Date
PC 97	February 9, 1998
PC 98	December 31, 1998
PC 99	July 14, 1999
PC 2001	November 2, 2000

PC 97

Initial version.
Introduced color code for PS/2 keyboard (purple) and mouse (green) connectors
PC 98

Aimed at systems to be used with Windows 98 or Windows 2000. Required:
200 MHz Pentium processor with MMX technology (or equivalent performance)
256 KB L2 cache
32 MB RAM (recommended: 64 MB of 66 MHz DRAM)
ACPI 1.0 (including power button behavior)
Fast BIOS power-up (limited RAM test, no floppy test, minimal startup display, etc.)
BIOS Y2K compliance
PXE preboot environment
It was published as ISBN 1-57231-716-7.
PC 99
Required:
300 MHz CPU
64 MB RAM
USB

Comprehensive color-coding scheme for ports and connectors (see below)
Strongly discouraged:
Non plug-and-play hardware
ISA slots
It was published as ISBN 0-7356-0518-1.

PC 2001
Final version. First to require IO-APICs to be enabled on all desktop systems. Places a greatly increased emphasis on legacy-reduced and legacy-free systems. Some "legacy" items such as ISA expansion slots and device dependence on MS-DOS are forbidden entirely, while others are merely strongly discouraged.

Color		Function	Connector on PC
Mouse and keyboard
	Green	PS/2 mouse / pointing device	6-pin mini-DIN female
	Purple	PS/2 keyboard	6-pin mini-DIN female
	Gold	Game port / MIDI	15-pin D female
General input/output
	White	USB 1 low speed and full speed	USB Type A receptacle
	Black	USB 2.0 high speed	USB Type A receptacle
	Sky blue	USB 3.0 SuperSpeed	USB Type A SuperSpeed receptacle
	Yellow	USB 3.0 SuperSpeed Always On even if the PC is turned off	USB Type A SuperSpeed receptacle
	Red	High-power USB (more than 500 mA current available)	USB Type A receptacle
	Grey	IEEE 1394 (FireWire)	6-pin FireWire 400 or 9-pin FireWire 800
	Burgundy	Parallel port	25-pin D female
	Teal or turquoise	Serial port	9-pin D male
Video
	Blue	Analog monitor	15-pin VGA female
	White	Digital monitor	DVI female
	Yellow	S-Video	4-pin mini-DIN
	Yellow	Composite video	RCA jack
	Black	Digital audio/video	HDMI or DisplayPort female
Audio
	Pink	Analog microphone audio input (mono or stereo)	3.5 mm TRS
	Light blue	Analog line level audio input	3.5 mm TRS
	Lime green	Analog line level audio output, front stereo (speakers or headphones)	3.5 mm TRS
	Black	Analog line level audio output, rear stereo (surround speakers)	3.5 mm TRS
	Orange	Analog line level audio output, center and subwoofer (surround speakers)	3.5 mm TRS
	Silver	Analog line level audio output, side stereo (surround speakers)	3.5 mm TRS
	Orange	Digital audio output (coaxial S/PDIF)	RCA connector
	Black	Digital audio output (optical S/PDIF)	TOSLINK

Source From Wikipedia