On 23 Oct 98 at 21:38, Dan Duffy wrote: > Hello and I sure hope someone can help me with this ram. > > I have a Microstar MS-6117 motherboard and bought a 64MB > EDO/ECC 8X72 168pin Unbuffered DIMM. The motherboard > manual says that it supports EDO and ECC. When I tried > to install it, one of the cutouts on the bottom of the DIMM > didn't match up with the (key?) on the motherboard DIMM > slot....it was about 1/16" off. I took another 168pin DIMM > and held them up to each other and they didn't match up. > Are there different sizes? of DIMM's or was this one just > cut wrong? Any help you can give me with this will be > most appreciated. There are two notches along the underside of DIMMs, and these indicate what voltage and technology is used. You are correct that this is a key -- a DIMM which will not fit because the notches are slightly off may not operat correctly in that motherboard. If this key scheme were really well implemented, it would be impossible to insert an incompatible DIMM, and easy to insert any compatible DIMM. Instead, we wind up with a case where compatible-but-non-default and incompatible DIMMs *may* be inserted if enough force is applied -- generally, the plastic pins that go through the notches will give before the fibreglass of the motherboard or DIMM breaks. I've never had this do permanent damage, but it did get pretty hot pretty fast.... My bottom line: If the notches don't line up, this isn't the sort of DIMM the motherboard was designed for, and your best bet is to determine what your board wants, and try to exchange/return and get the right kind. David G ----- PCBUILD mailing list - http://nospin.com Bob Wright:[log in to unmask] - Drew Dunn:[log in to unmask]