문득, PS/2 마우스와 키보드를 바꾸어 꼽으면 작동을 안한다는 말을 들었었고,
USB -> PS/2 키보드
USB -> PS/2 마우스 용 젠더가 별도로 존재하는것으로 알고 있어서 한번 검색을 하게 되었는데


The PS/2 connector is used for connecting some keyboards and mice to a PC compatible computer system. Its name comes from the IBM Personal System/2 series of personal computers, with which it was introduced in 1987. The PS/2 mouse connector generally replaced the older DE-9 RS-232 "serial mouse" connector, while the PS/2 keyboard connector replaced the larger 5-pin DIN used in the IBM PC/AT design. The PS/2 designs on keyboard and mouse interfaces are electrically similar and employ the same communication protocol. However, a given system's keyboard and mouse port may not be interchangeable since the two devices use a different set of commands.


Data signal Serial data at 10 to 16 kHz with 1 stop bit, 1 start bit, 1 parity bit (odd)

Female connector from the front
Pin 1 +DATA Data
Pin 2 Not connected Not connected*
Pin 3 GND Ground
Pin 4 Vcc +5 V DC at 275 mA
Pin 5 +CLK Clock
Pin 6 Not connected Not connected**
* On some laptops mouse data for splitter cable.

** On some laptops mouse clock for splitter cable.


Legacy port status and USB

Today's laptops frequently do not include PS/2 ports and so the port is now regarded as a legacy port on Wintel, having been superseded by USB. Many current keyboards and mice support both USB and PS/2 with a simple wiring adapter and active adapters are available which plug into a USB port and provide a pair of PS/2 ports (active adapters in the other direction are very rare). PS/2 ports however, can still be found on modern desktop computer motherboards, although a few newer motherboards have no PS/2-port or only the keyboard port, but most still have them. These PS/2 ports cause fewer problems when KVM switching with non-Wintel systems.

[링크 : http://en.wikipedia.org/wiki/PS/2_connector]



Width in bits: 1
Number of devices: 127 per host controller
Capacity 1.5, 12, or 480 Mbit/s (0.2, 1.5 or 60 MByte/s)
Style: Serial

[링크 : http://en.wikipedia.org/wiki/USB]

어떻게 보면, 저속의 USB 장치로 PS/2를 연결하면 되겠다 싶기도 했지만
음.. 그냥 내부적으로 USB와 PS/2를 자동인식해서 그에 맞는 방법으로 전송을 하는것으로 보인다.
어짜피 둘다 실질적으로 4개 선을 이용하니, 핀이 다르게 사용하면
4개의 선으로 마우스/키보드를 USB로 별다른 차이점 없이 가능할듯 하다.

확실한 전기적 차이점은 없지만, (둘다 5V, PS/2는 250mA, USB는 500mA까지 흘려줌)
일단 datarate가 다르고, 신호가 다를테니 머.. 그건 하드웨어 개발자가 알아서 할일인가 -ㅁ-?
Posted by 구차니
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