power supply +5V pinouts for laptops

[Muxau^]

hello, I found a AST old laptop without batery or power supply.

The power connector is like ps/2 mouse but with 8 pins in 3 rows
it writes  it is 5V .
Some Hewlett Packard external CD writers have the same connector

o o  o
o  o o
 oo  

please tell me if you know where is "plus" and "-"GND.

where I can find pinouts for different old laptop's power supplies?
thank You.