Curious... How does the BIOS know how much memory is installed?

[MarkS]

This is something that I never understood. How does the BIOS know (I assume that the OS gets this info from the BIOS) how much is installed? Is there something about the wiring on the actual sticks that tells the total size per stick? I know that DRAM chips don't expose this info and it isn't exposed with the way the memory is addressed.

Something on the sticks must report this information? Correct?

[Short Circuit]

correct.
http://en.wikipedia.org/wiki/Serial_presence_detect

[MarkS]

Thank you.