VAX 6000


The VAX 6000 was a family of minicomputers developed and manufactured by Digital Equipment Corporation using processors implementing the VAX instruction set architecture. Originally, the VAX 6000 was intended to be a mid-range VAX product line complementing the VAX 8000, but with the introduction of the VAX 6000 Model 400 series, the older VAX 8000 was discontinued in favor of the VAX 6000, which offered slightly higher performance for half the cost.

Cabinet

The VAX 6000 was housed in a cabinet which contained three card cages in the upper portion: a 14-slot XMI card cage on the right for CPU and memory modules, and optional VAXBI Bus hardware on the left. The VAXBI hardware distinguished two versions of the VAX 6000 platform, XMI-1 and XMI-2. XMI-1 differed from XMI-2 by requiring a DWMBA adapter and the presence of two 6-slot VAXBI channels, whereas in the XMI-2 platform, VAXBI was an optional feature and, if required, it was provided as a single 12-slot channel. In both versions, VAXBI was provided by two 6-slot VAXBI card cages.
Below the card cages was the cooling system, which took up most of the volume in the cabinet. The bottom of the cabinet contained a provisions for an optional battery backup unit and two RA90 or RA92 hard disk drives. The battery backup unit could provide power to the system for one second in the event of a power failure, after which the system ceased to operate, but continued to preserve the data in the cache and memory for ten minutes.
The cabinet was 154 cm high, 78 cm wide and deep; and weighed 341 kg.

VAX 6000 Model 2x0

The VAX 6333 was a prepackaged VAXcluster of three VAX 6330 systems. Bundled with the SA650 Storage Array, the VAX 6333 cost US$2.8 million.

VAX 6000 Model 4x0

The VAX 6000 Model 4x0, code-named "Calypso/XRP", was introduced on 11 July 1989. It used the KA64A CPU module and could be configured with one to six such modules for one to six processors. The KA64A contained a 35.71 MHz Rigel chip set with an external 128 KB B-cache. The B-cache was direct-mapped and used a 64-byte cache line size with a 16-byte sub-block size. It was constructed from twenty-four 64 KB 15 ns SRAMs. The module also contained a REXMI chip set, whose purpose was to interface the Rigel chip set's DAL bus to the XCI ASIC, the user side of the XMI corner interface. The REXMI chip set was composed of the XCA controller/address chip and two XCP data path chips. The XCA and XCP were ASICs developed using a standard-cell methodology and fabricated in Digital's CMOS-2 process. The Rigel chip set's DAL bus was interfaced to the XMI corner and then to the XMI bus by the REXMI interface. A maximum of 256 MB of ECC memory was supported.

VAX 6000 Model 5x0

Code-named "Neptune", it was introduced on 30 November 1991. The Model 600 used the KA66A CPU module, which contained an 83.33 MHz NVAX microprocessor accompanied by an external 2 MB B-cache and may have one to six such modules. The NVAX was connected to the NEXMI ASIC via the NDAL bus, a 64-bit address data multiplexed system bus clocked at 27.78 MHz. The NEXMI ASIC interfaced the NVAX to the XMI2 bus, by providing functions such as the translation of NDAL bus commands to XMI bus commands. It also implemented the ROMBUS used by supporting devices on the CPU module such as the console. The NEXMI was a semi-custom ASIC fabricated in Digital's CMOS-3 CMOS process. It contained 0.25 million transistors on a 0.595 by 0.586 inch die packaged in a custom 339-pin ceramic pin grid array. The system supported a maximum of 1 GB of memory.