Bus mouse

Bus mouse
A Microsoft InPort bus mouse adapter, in the form of an 8-bit ISA (XT-bus) card
Type Computer mouse input port
Production history
Designer Microsoft
Designed late 1980s
Produced 1980s to 2000
Superseded by PS/2 port, USB (2000; 24 years ago (2000))
General specifications
External Yes
Cable 9 wires plus shield
Pins 9
Connector Mini-DIN-9
Data
Data signal 30–200 Hz (interrupt mode) with 3 button state signals and quadrature signals for mouse movement
Pinout
Female port pin layout from the front
Pin 1 SW2 Mouse button 2
Pin 2 SW3 Mouse button 3
Pin 3 GND Ground
Pin 4 XB X position
Pin 5 YA Y position
Pin 6 YB Y position
Pin 7 SW1 Mouse button 1
Pin 8 Vcc +5 V Power
Pin 9 XA X position
XA/XB and YA/YB indicate movement and direction based on quadrature phase.

A bus mouse is a variety of PC computer mouse which is attached to the computer using a specialized interface (originally, the Microsoft InPort interface developed for Microsoft's original mouse product).

Microsoft InPort bus mouse
Microsoft InPort™ bus mouse, showing the 9-pin round connector
Label from Microsoft InPort mouse
Label on the bottom of a Microsoft InPort™ bus mouse, showing the FCC ID "C3K7PN9937"

In the late 1980s, mice were not integrated with IBM-compatible personal computers, and the specialized bus interface (implemented via an ISA add-in card) was one of two popular ways to connect a mouse; serial interfaces were the other method. In addition to Microsoft, Logitech also made bus mouse interface cards.

When the IBM PS/2 was introduced, it included a motherboard mouse interface which was integrated with the keyboard controller (still called the PS/2 mouse interface long after the PS/2 brand was withdrawn); this fairly quickly drove the bus mouse design out of the marketplace.

The bus mouse lived on in the NEC PC-98 family of personal computers in Japan.