What happens when one inverts mouse clk and data in a ps/2 connector?

[dencorso]

Hi! I'm trying to figure out the correct pins in an old PCChips board. It's a M598. I have the manual but it has a figure describing the J1 (ATX Form Card) Conector but it is the mirror image of the actual connector. With some guesswork and a multimeter I've already found the correct pins for the USB1 and USB2 connectors and +5V and GND for the ps/2 mouse connector. I also know the pair of pins that are CLK and DATA, but I couldn't think of any way to distinguish which is which. So I gambled, and selected one of the possibilities at random and the mouse is working normally. Now I'm thinking is there any way to do it without the gamble if you don't have an oscilloscope at hand? Can the wrong choice damage the mouse (it seems to me that there is not such danger, as both are open-cathode, and very similar in what regards connection and voltages)? Would the mouse behave strangely if connected with DATA and CLK reversed? Please advise. I've already searched the net high and low but found no answer to these questions.

[jaclaz]

As long as you do not invert the power lines, the mouse will either work or work not. (CLK is monodirectional, DATA is bidirectional)

Even if you QUICKLY try with the power lines inverted, the mouse chip won't be damaged, but it will HEAT quickly, and you know you have inverted them.

The PS/2 type of mouse uses ANYWAY +5V, so there won't be problems (there may be problems with a Serial mouse):

http://pinouts.ru/Inputs/PS2Mouse_pinout.shtml

jaclaz

[dencorso]

As long as you do not invert the power lines, the mouse will either work or work not. (CLK is monodirectional, DATA is bidirectional) [...]

Thanks a lot, jaclaz, you rock!

[jaclaz]

Additional info that may be of use:

http://www.computer-engineering.org/ps2protocol/

jaclaz