9000 VAX wrote: The MicroVAX 3900 is rackmount only if you carefully remove the skins. It includes an RA8x (maybe even RA9x) only if it comes in an H9xxx cab (forget the exact number). The usual MicroVAX 3900 came in a BA213 (skunk box). The MicroVAX 3800 came in the slightly smaller and slightly less heavy BA215. You can find all sorts of info by heading over to Manx: http://vt100.net/manx and looking for BA213, BA215, KA650, KA655, MicroVAX 3800 and MicroVAX 3900. If that isn't enough reading, you can look here: http://www.mcmanis.com/chuck/computers/vaxen/fastvax.html for a BA213 and here: http://www.users.bigpond.com/vk3jaj/uvax3k5/ You should be able to find plenty more with google. Basically the 3200/35003600 use a KA650 and the 3800/3900 use the slightly faster KA655 processor. Almost everything is interchangeable between the various versions. Antonio -- --------------- Antonio Carlini arcarlini at iee.org