deciphering memory chips

On Jan 26, 11:41, Teo Zenios wrote: you have? Usually, Google. I didn't find any hits for KM428C25J-6 or KM428C25J or KM428C25 or ... but I did find some for KM428C256 (which makes more sense, actually). The other thing I use is a fairly large collection of data books. Never discard data books :-) And I just happen to have a Samsung 1994 Product Guide that lists the KM428C256. Being only a Product Guide, it doesn't give details, but it says its a 2Mbit device organised as 258K x 8, and there are several speed variants as well as a V256, and C257/V257. KM is Samsung. 4 means DRAM, 42 means VRAM. 8 means 8 bits wide. C means 5V CMOS, V means 3.3V CMOS. 256 is the density and organisation, in this case 256K Page Mode. 257 means "E/F" mode (I can't think what that stands for, off the top of my head). J means SOJ (P is DIP, Z is ZIP, T is TSOP). The -6 means 60ns (-7, -8, -10 are also common). As you probably know, VRAM is dual-ported RAM, so that the graphics display hardware can read it without interfering with writes from the graphics engine or CPU. This particular type is used in some old SGI video systems. You mean like a PLCC but with pins on only two sides, sort of like a DIL chip? It's called SOJ, or more specifically, xx-SOJ-y00, where xx is the number of pins and y00 is the spacing between the two rows in 1000ths of an inch (so 300 means 0.3"). or edo ram. I don't think so. But I'm not an expert on video cards. -- Pete Peter Turnbull Network Manager University of York