PS2 Mouse and Keyboard Connector
Pinout
The keyboard and mouse connector are 6-pin miniature DIN
connectors. The signals and voltages are the same for both connectors.
|
|
Signal: 1: data 2: reserved 3: ground 4: +5V dc 5: Clock 6: reserved |
PS2 Signal levels
The keyboard and auxiliary device signals are driven by open-collector drivers
pulled to 5Vdc through a pull-up resistor.
|
Sink current Max |
20mA |
|
Hi-level output V Min |
5.0 Vdc - Vdrop_pullup |
|
Low-level Output v Max |
0.5 Vdc |
|
High-level input v Min |
2.0 Vdc |
|
Low-level input v Max |
0.8 Vdc |
Serial Mouse to PS2
Conversion?
The "Serial Mouse" uses a RS-232 style interface with -5
to -12 VDC as logical "1" and +5 to +12 VDC as logical "0".
The PS/2 mouse interface is a TTL-style interface, which uses 0 - +2 VDC as
logical "0" and +3 - +5 VDC as logical "1".
In addition - and to make things worser - the RS-232 is an
asynchronous interface, the PS/2 interface is a synchronous, where the data is
sent along with a clock signal. It uses a simplified 4-wires serial interface
with +5VDC (for the transceiver), GND, keyboard / mouse clock and keyboard /
mouse data. The data and clock line can be used from the keyboard / mouse
controller and the attached device as well following a particular handshake,
which defines which is the active "sender" and which is the
"receiver". So: it is not *that* easy conversing serial mouse to PS/2
and vice versa.
The "dual mode" mice have an automatic logic detection
and sort of adaptive interface electronic, which detects whether the mouse is
attached to a serial port or a PS/2 port and set the output drivers
accordingly.
As you can see from the above: it is not enough only *physically*
changing the plugs.