I just recently recieved an IBM PC AT Computer in the mail. It turns on and tries to read from the floppy disk drives and hard drive but the cmos battery is dead. It gives me error 161 and says to enter setup. The people on ebay told me it was dead so I bought it thinking I could find the cmos bettery on the motherboard. Well, I have had no luck finding anything that looks like a cmos battery. I have no idea what a cmos battery looks like in an IBM AT so I need someone to tell me what it looks like, or just send me a picture, or tell me where it's located. There are many little chips on the mobo but I can't seem to find out which one it is, or maybe its attached somewhere in the case that I can't see. If someone could help me with this, I would be very grateful. Also could someone tell me what I press on the keyboard to enter the setup on an IBM AT, because I couldn't figure it out. Thanks.