Hi, quick question, I had this old pc given to me and I noticed I had 2 Slots(black in color)and I have PC133 256MB that I would like to install. Is it possible? I know I should remove the old memory bars first. Not Sure if there SIMM or DIMM. It's a Pentium 166 MHz. I just want to know if its possible to do, and I won't burn out anything. Thanks in advance.

Some socket 7 boards have both simm and dimm slots but obviously you can't use both at once...so yeah if they are dimm slots you can put your 256 pc133 in it and remove the existing memory...unless the existing stuff is dimms then you can add to it.. If that 256 is high density the old chipset on the mobo may only recognise half of it though.

1. Get a manual. If you have no idea what you have, if the mboard is working, If you have internet access: Go here, download BIOS AGENT. Run BIOS AGENT to find your bios string. Tell us the bios string it finds, and include any dashes, etc. Tell us everything Bios Agent finds. http://www.wimsbios.com ... If you do not have internet access, the bios string is usually a long string of numbers/letters at the bottom of the first black screen as you boot your computer - usually you can press the Pause key to read it and copy it down. It could also be higher up the screen under the bios version line, e.g. under the line Award 4.51 pg. Send this bios string to us, and include any dashes, etc. ...... If the mboard is not in a working system, look for model numbers or other numbers on the mboard and tell us what you find. Numbers on the bios are usually useless. 2. PC133 SDRam is backward compatible with PCxxx and must use 3.3 volt Dram ram sockets. Early mboards may be 5 volt only (FPM or EDO DRAM only; some can't use EDO) and can't use SDRam, or the voltage may have to be chosen by jumper, or the mboard chipset may auto find the right voltage (not likely for your old mboard). 3. Assuming you can use SDRam on that old mboard, mboard must be able to recognize 256mb modules - many early mboards cannot - my 1999 mboard cannot. 4. Even if everything else complies, some modules do not work in some mboards - it's a crap shoot - symptoms range from no boot to recognized as smaller to cancelling out the recognition of another module, etc. New 4 chip ram does not work in a lot of older mboards. 5. If you have both 72 pin SIMM sockets (usually white) and 168 pin DRAM sockets (usually black), on some mboards it is much easier to find compatible 72 ram (must be identical spec pairs) than it is 168 pin ram. 6. On the other hand, SDRam is up to 4 times more efficient than 72 pin ram.