A Microsoft InPort bus mouse adapter, in the form of an 8-bit ISA (XT-bus) card.
|Type||Computer mouse input port|
|Produced||1980s to 2000|
|Superseded by||PS/2 connector, USB (2000)|
|Data signal||3 button state signals and quadrature signals for mouse movement|
|Pin 1||SW 2||Mouse button 2|
|Pin 2||SW 3||Mouse button 3|
|Pin 4||XB||X position|
|Pin 5||YA||Y position|
|Pin 6||YB||Y position|
|Pin 7||SW1||Mouse button 1|
|Pin 8||+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).
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, common on engineering workstations, were the other method.) 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which was integrated with the keyboard controller (still called the PS/2 mouse interface long after the PS/2 brand was withdrawn); this fairly quickly drove the bus mouse design out of the marketplace.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.