Hello! Mark can you provide a pointer to this HP Microserver? And go ahead and roll on the floor laughing, but I've been tempted to track down a PDP-11, when I first saw and actually wanted a PDP-8 to work with. My >father convinced me that doing so would be problematic because the poor thing had only 8K of core based memory. Is our friend behind the E11 subscribed here? He'll know what style of wire wrapping based board I have here. It's designed for the PDP-11, I think it >>might be the Q-Bus style one.... ----- Gregg C Levine gregg.drwho8 at gmail.com "This signature fought the Time Wars, time and again." Greg, This is simple. If the backplane has 2 slots per row then it is a QBUS (/2 variant). If it has 4 slots per row then it is also QBUS but could be either 18-bit or 22-bit - the part number on the side of the backplane will tell you for sure. If the backplane has 6 slots per row then it is UNIBUS. -Steve