Bus mouse

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).

Bus mouse
ISA mouse adapter.JPG
A Microsoft InPort bus mouse adapter, in the form of an 8-bit ISA (XT-bus) card.
Type Computer mouse input port
Designer Microsoft
Designed late 1980s
Produced 1980s to 2000
Superseded by PS/2 port, USB (2000; 20 years ago (2000))
External Yes
Cable 9 wires plus shield
Pins 9
Connector Mini-DIN-9
Data signal 30–200 Hz (interrupt mode) with 3 button state signals and quadrature signals for mouse movement
MiniDIN-9 Diagram.svg
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.
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, 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which was integrated with the keyboard controller (still called the PS/2 mouse interface long after the PS/2 brand was withdrawn); this fairly quickly drove the bus mouse design out of the marketplace.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.

See alsoEdit

Further readingEdit

  • Paul, Matthias R. (2002-04-06). "Re: [fd-dev] ANNOUNCE: CuteMouse 2.0 alpha 1". freedos-dev. Archived from the original on 2020-02-07. Retrieved 2020-02-07. […] The original Mouse Systems Bus Mouse is a normal serial 8250 compatible mouse using the normal Mouse Systems serial protocol, however the base address of this 8250 type chip is not one of the usual COM port addresses 3F8h, 2F8h, 3E8h, or 2E8h, but either 238h or 338h. Besides others these addresses are also supported as alternative addresses for serial ports on the German c't UniRAM add-on ISA card. […] Bus mice from other vendors use completely different interfaces, partially residing at the same I/O addresses […]

External linksEdit