Hello,

> The question I have now: my box reports a "ki2c0 at obio0" and it has
> a fan, but I never heard it run, even though the machine got quite hot
> at times. Does it mean that there hides a fan somewhere behind that
> interface and that it is currently uncontrolled and therefor always off?
Depends, ki2c is an I2C bus controller, there may be one of more fans, various sensors and whatnot connected to it. Look at your OpenFirmware device tree, there should be at least one i2c@whatever device, then look at their child nodes / properties :)

In my iBook G4 there are 3 I2C buses, two are ki2cs. The one seen by NetBSD is in the mac-io chip and has no fan or sensor connected, but there is another one in /uni-n/i2c which does. Even in NetBSD the fan runs now and then, so it's apparently controlled by something else than the OS.

have fun
Michael