hour meter

Do you mean something that tells you how long the computer has been on?

You can use Terminal.app and execute the command 'uptime' to find out how long the machine has been running since the last startup/reboot.

There's also sharware programs out there that will monitor the system's sleep periods if this is of interest.

I don't know how familiar you are with the Terminal, Daniel.

It is in your Applications > Utilities folder. After you launch it, type "uptime" (minus the quotation marks), and then hit the return key.

I have always wished this would be a feature on computers.
Sortof like an Odometer except for computers.
I think it would be possible to put something like this in the firmware so that an OS reintall wouldnt reset it.

I don't think there is anything like that.

You can go to Apple's Home page and put your serial number in the box at the bottom right, and it will give you information about your computer, including warranty information.

Daniel:

If you open and close you iBook's screen 6500 times the screen will go black. Just kidding now.

There's no hour meter as you described for any user-level Apple computer. Some machines have this I know as it's used for knowing when to do maintenance activities.

About the only thing I can think of would be to ALWAYS have your iBook connected to the main line power supply and have the wall plug plug into an hour meter or energy use meter.

Interesting question.

syslogd has the ability to generate "mark" messages every X minutes, so you could set this to occur every minute and count the number of marks to know how many minutes the machine has been awake (±1, since you could awaken or go to sleep "in the middle of a minute" and lose that minute's mark). Direct the heartbeats to system.log and have the log rotation script count them and update a counter in some persistent file. Hm, even better, have a dinky script that just increments the counter by 1 every time it runs, and direct the heartbeat msg to triggr that script. Well heck...no need even for syslogd...just have a cron job that just runs that script every minute...now it can be a completely user-land thing instead of requiring admin access to configure it.

Edit: Unfortunately, none of this this works during sleep. And it may not even be possible to detect sleep (since nothing's running). You could detect wake-up and trace back to when sleep began, but if you sleep for 6 hours and then crash hard or lose power, you "lose" those 6 hours. It's easy to measure the times between each startup and the following shutdown, but again a hard crash prevents recording of the shutdown timestamp.