On Sat May 24 19:36:25 CDT 2014, St?phane Tsacas wrote: These are CAMAC modules that have a dual-wide qbus connector on-board. An actual DEC board plugs into the slot. There is a black metal cover that holds the board in place. The 3823 housings carry the 11/23 CPU, while the 3824's carry the support modules (serial lines, memory, etc.) The problem is -- with the metal cover in place, you can't tell what you're getting. The DEC module could be missing. It could be an 11/23 without an MMU. Or, you might end up with just the shell, and no DEC board at all. For the 3824 modules, with the cover in place you can't see what kind of module is installed. So, you could spend $50, and get a crummy M8044, or you might end up with an M7195 at a bargain price. Unfortunately, many sellers only show the front and back, so it's best to ask them questions before buying. T