variants of the MS630 existed: the 1 MB MS630-AA, 2 MB MS630-BA, 4 MB MS630-BB and the 8MB MS630-CA. The MS630-AA was a dual-height module, whereas the MS630-BA, MS630-BB and MS630-CA were quad-height modules. These modules used 256 Kb DRAMs and were protected by byte-parity, with the parity logic located on the module. The modules connected to the CPU module via the backplane through the C and D rows and a 50-conductor ribbon cable. The backplane served as the address bus and the ribbon cable as the data bus. The MicroVAX II came in three models of enclosure: BA23 BA123 630QE - A deskside enclosure. KA620 KA620 referred to a single-board MicroVAX II designed for automatic test equipment and manufacturing applications which only ran DEC's real-time VAXELN operating system. A KA620 with 1 MB of memory bundled with the VAXELN Run-Time Package 2.3 was priced at US$5,000. Mira Mira referred to a fault-tolerant configuration of the MicroVAX II developed by DEC's European Centre for Special Systems located in Annecy in France. The system consisted of two MicroVAX 78032 microprocessors, an active and standby microprocessor in a single box, connected by Ethernet and controlled by a software switch. When a fault was detected in the active microprocessor, the workload was switched over to the standby microprocessor. Industrial VAX 630 A MicroVAX II in BA213 enclosure. MicroVAX III BA23- or BA123-enclosure MicroVAX upgraded with KA650 CPU module containing a CVAX chip set. MicroVAX III+ BA23- or BA123-enclosure MicroVAX upgraded with KA655 CPU module. VAX 4 BA23- or BA123-enclosure MicroVAX upgraded with KA660 CPU module. MicroVAX 2000 The MicroVAX 2000, code-named TeamMate, was a low-cost MicroVAX introduced on 10 February 1987. In January 1987, the MicroVAX 2000 was the first VAX system targeted at both universities and VAX programmers who wanted to work from remote locations. The MicroVAX 2000 used the same microprocessor and floating-point coprocessor as the MicroVAX II, but was feature reduced in order to lower the cost. Limitations were a reduced maximum memory capacity, 14 MB versus 16 MB in MicroVAX II systems and the lack of Q-Bus or any expansion bus. The system could have a Shugart-based harddrive with ST412 interface and MFM encoding and had a built in 5.25-inch floppy drive (named RX33 in DEC jargon) for software distribution and backup. Supported operating systems were VMS and ULTRIX. It was packaged in a desktop form factor. MicroVAX 3100