Wow... $1149 for 28 lbs. The first one is an adapter for next generation CPU validation. It would be used to verify new chip design functionality by plugging into a known good motherboard design that used the previous generation. Probably running at a much slower clock speed to be compatible. The second and third are also adapters for the same purpose but used in place of an MCM (Multi-Chip Module). MCMs usually had much larger cache, ALU or geometry acceleration that simply wouldn't fit into a single die using the current die technology at the time. From the looks of it, this was probably 1992-96 technology. The difference between 2 and 3 could be different MCM types or a test of 2 design/layout possibilites. These might go into temporary prototype production for software development until the motherboard design could catch up. A few might even go to select customers to build future business confidence. If anyone is interested, I'll post a photo of an MCM I have with dies exposed. It has gold everywhere. It actually has pure gold trace layers in the white ceramic between the dies and from the bond out wires to motherboard pins instead of package wires. It's kind of like a miniature multi-layer PCB but in ceramic. Hey, maybe we need a section like the current "Show Us Your Nuggets" Gallery but for unusual gold bearing pieces we find?