Have a Quantex system/motherboard 8500 TAC VER. 1. System is almost 6 years old and think that I should change the cmos battery. Trouble is I can't indentify it. The only object I think it might be is an 3/4x3/4" covered box next to the ps2 rec.(keyboard). System is still working fine with many upgrades over the years but why wait for the end. Also where can I find a replacement

Some batteries in older systems don't look like a battery at all. DALLAS was one of the major manufacturer's of Batteries disguised as little black boxes. Look for a thingy labeled DALLAS. Hopefully, if you have one of these, you can find jumpers on the motherboard that disable the onboard battery when it goes belly up. Then there should be a 4 pin connection on the board somewhere that is for an external battery. One of the 4 pins might be missing. Hopefully you have some silk screened legends on the motherboard (or not), that explain all the jumper settings.

If it's not a Dallas RTC, then you should see at least a red and a black wire coming from the battery to the mobo. It's good to know where it is, but they often can last an Awfully long time. I've got an old 386 from 1989 - battery's still fine.

Some batteries are a light blue or orange or red & black cylinder soldered near the keyboard jack. They can become quite corroded on the ends. The later Dallas ones could be replaced. Earlier ones are soldred in. They are about 1/2" wide buy 3/4 inch long and black. Normally on the edge of the m/b.

Mine is soldered in on my 386 ps/2. It is a dallas battery & it is dead. When I turn it on I have to start it with a ps/2 reference disk then it funtions normally. I really do want a battery though. I wrote in here once about it & someone said it was not worth it. That it would cost more than the machine was worth. But for some reason I want it fixed though. I like it.

It is possible to repair dead (DALLAS) cmos battery. Battery is located on top side of cmos chip. It is molded in not a very hard plastic. You can cut it with sharp blade (e.g. olfa). Be careful: on one side of chip there is a quartz crystal (small), on the other side is the battery. It is wide almost as chip. Remember where is plus (+). Remove bad battery and solder a new one (3 V Lithium). Why to repair battery chip? It is difficult to get some old types, and it is cheaper,... I've repaired (successfuly) about 20 batteries ( for PC and SUN machines).

Right on, j. Another blacksmith ;-) I had a non-erasable dallas chip (DS1287)that had become corrupted by a virus and I ground the top off, cut the battery connection to clear the cmos and re-connected it. Works fine again.