Where does a mac save information on the selected startup disk

[HateEternal]

I a working on a iMac that was brought in, when it came in it would not detect any bootable OS on the Hard drive, so I put in my OS X BootCD and after it booted it read the hard drive fine. I opened Sys pref and went to start up disk, it found 10.0.3 and 9.2.2 as bootable OS's on the disk. I selected one of them and it works fine booting from it.

Now, I noticed when it booted the first time it gives the incorrect time/date error, which leads me to believe that the battery is dead. Would this effect where the startup disk setting is saved.. which might have caused it to forget what to boot from?

I really only want to know because I don't want to give this guy his computer back and have the same thing happen again.

 

[ElDiabloConCaca]

Yes -- a dead battery can affect everything from incorrect date/time settings to inablility to "remember" the startup disk.

The startup disk setting is retained in the computer's NVRAM, or non-volatile RAM, which, incidentally, is kept "alive" by the motherboard battery when there's no power to the computer.

 

[perfessor101]

... which, incidentally, is kept "alive" by the motherboard battery when there's no power to the computer.

Except in the case of the iBook and some PowerBooks that have no battery on the motherboard, relying instead on the main system battery.