Can somebody explain the difference between the terms BIOS and CMOS? They are related, right? I know that BIOS is basically ROM that is housed on the motherboard and provides basic operating instructions, right? CMOS, on the other hand, is what? Thanks for clarifying....

CMOS=Complementary Metal-Oxide Semiconductor PCs typically have 64 bytes of CMOS RAM, and this is used to store configuration information, such as the number and types of diskette drives and COM ports which are installed. BIOS=Basic Input/Output System. This is the low level routines (programs) that provide standard program interfaces to perform hardware-oriented functions such as reading the keyboard, writing to the monitor's screen and accessing disk drives.

So is CMOS a piece of memory hardware, similar in theory to the RAM you would install on your motherboard? If it stands for Complementary Metal-Oxide Semiconductor it sounds like a piece of hardware and not operating code. If it is RAM, the information stored on it can get updated as components change, etc? Is there a "setup" screen to access CMOS, and if yes, under what circumstances would you want to do that? Where does the BIOS reside? Is there a chip or something on the motherboard that houses this input/output code? I'm assuming this is hardwired into the chip (like ROM) and is not changed? Sorry to be a pain about this, but I just want to get a firmer understanding of some of the inner workings.Thanks,

This page explains it better then I can in this forum: BIOS/COMS They also answer other hardware questions you might be interested in.

Good site, good info for newer pc users. Johnson, basically the CMOS is a watch battery, so to say. When you change something in the BIOS (like say you have onboard video, but you add a new graphics card, you have to go into the BIOS and tell it to use the new card in the pci or agp slot instead of the onboard card) it will ask you to save the changes. When you save these, it writes it into the cmos battery. CMOS is why your computer holds the time when the computer is off. It basically stores the BIOS settings. All this was probably on that page though. Cheers, William