11

In the below image (from here), the "left" end (which I have labeled "A") is clearly two PS/2 ports.

What is the "right" end (which I have labeled "B")?
Does it connect directly to a motherboard?

Cable

The above is apparently Lenovo part number 43N9149, but I haven't been able to find an actual specification sheet for this part -- only third-party seller listings on Amazon, eBay, and the like.

ADDENDUM

I need to be able to use a PS/2 mouse with a Lenovo ThinkStation that I am considering. The particular system I am considering does not have a built-in PS/2 port, but Lenovo sells the above part as an add-on. The problem is, on my existing desktop (not Lenovo) I have tried external USB to PS/2 adapters (dongles) from third-parties, and I have experienced a significant latency issue when I connect a mouse to it. I mean, cursor movement on my screen significantly and noticeably lags the physical movement of my mouse with such external dongles. I'm hoping that the "B" end above has a faster connection than an external USB connection would have.

  • 1
    Thats totally not true @mins! USB and PS/2 are entirely different signals. All Devices that work with passive converters support both signals! You can't use any device supporting only PS/2 in a USB port with a passive "converter". – Josef says Reinstate Monica Jun 15 '15 at 6:59
  • @Josef. I stand corrected. This is the device which senses the host it is connected to, and send the proper signal. Thanks for pointing it out. – mins Jun 15 '15 at 7:42
  • Do you intend to unplug/replug the PS/2 mouse to this connector? (Your phrase "when I connect a mouse to it" prompts this question. I hope you do not mean that you (dis-)connect the mouse while powered.) – Eric Towers Jun 15 '15 at 13:45
20

B-end is a Lenovo-specific 7-pin PS/2 connector, which you connect straight to Lenovo motherboard. See 3rd image from this auction for the details:

http://www.ebay.com/itm/Lenovo-ThinkStation-ThinkCentre-FRU-43N9149-PS-2-Keyboard-Mouse-Cable-/251535857927

  • Thanks. Could you look at the "addendum" I added in my original question and see what you think? – Andrew Jun 14 '15 at 21:59
  • 3
    Avoid USB to PS/2 adapters, all of them are problematic. Just buy this cable from photo. – Tomasz Klim Jun 14 '15 at 22:03
7

This 7-pin connector goes to a header on a Lenovo motherboard marked KB/MS (keyboard/mouse), specifically for interfacing the motherboard to PS/2 ports.

The header

According to the Lenovo forums, the pinout is as follows:

/-------\
|4|3|2|1|
| |7|6|5|
\-------/

Pin 1 - 5V
Pin 2 - CLK
Pin 3 - Data  [5V]
Pin 4 - GND
Pin 5 - 3.3V
Pin 6 - GND (noisy)
Pin 7 - Data  [5V]

There is no official spec available.

4

It is the keyboard / mouse port for the computer. Yes, port B connects directly to the motherboard. Depending on the age of the computer, it could either connect to a USB connector or to serial controllers for the keyboard and mouse.

  • One reason that I asked this question is that I need to be able to use a PS/2 mouse with a Lenovo ThinkStation that I am considering. The particular system I am considering does not have a built-in PS/2 port, but Lenovo sells the above part as an add-on. The problem is, on my existing desktop I have tried external USB to PS/2 adapters (dongles) from third-parties, and I have experienced a significant latency issue when I connect a mouse to it. If the above has a USB internal connector end, is there any chance I would experience less latency than with an external dongle? – Andrew Jun 14 '15 at 21:50
  • 1
    Since they sell it as an add-on, it would work on your system. I'm not familiar with the ThinkStation's motherboard to be able to tell you about the latency. – LDC3 Jun 14 '15 at 21:59
1

Looks like a USB internal connector. It should connect to the motherboard in the same header as what you would connect the 'front' USB on your case.

USB Headers

Though, given that it is a lenovo specific adapter, it could be specifically designed for a motherboard in one of their machines. Just check that the pins lines up (there's a covered over hole on the adapter and a missing pin on the headers, they should line up.)

  • Thanks. Do you think it is a USB 2.0 or USB 3.0 internal connector? I know it might be impossible to say. – Andrew Jun 14 '15 at 21:42
  • 14
    It's not 10-pin USB connector. It's 7-pin dual-PS/2 Lenovo-specific connector. – Tomasz Klim Jun 14 '15 at 21:45
  • @TomaszKlim So probably (at least ideally) I will not necessarily experience the same latency issues as I did with external USB to PS/2 adapters (dongles) from third parties? – Andrew Jun 14 '15 at 21:53
  • 5
    When you force connect your 7-pin cable to this 10-pin connector, you won't experience any latency issues, because you'll burn your USB controller immediately :) – Tomasz Klim Jun 14 '15 at 21:59
  • 3
    But seriously, PS/2 mouse will be faster, but USB mouse with vendor drivers can be more precise. – Tomasz Klim Jun 14 '15 at 22:00
0

/-------\

|4|3|2|1|

|X|7|6|5|

-------/

Pin 1 - 5V (Keyboard & Mouse)

Pin 2 - Keyboard CLOCK

Pin 3 - Keyboard Data

Pin 4 - GROUND (Keyboard & Mouse)

Pin 5 - No connection

Pin 6 - Mouse CLOCK

Pin 7 - Mouse Data

Pin X - Connector Orientation KEY

Keyboard & Mouse mini-DIN-6 pinouts from http://www.burtonsys.com/PS2_keyboard_and_mouse_mini-DIN-6_connector_pinouts.html

Built from scrap parts and it works.

  • 1
    How is this answer different from oldmud0's? – robinCTS Jun 26 '18 at 3:41

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