DEC 4000 AXP
Encyclopedia
The DEC 4000 AXP is a series of departmental server computers
developed and manufactured by Digital Equipment Corporation
introduced on 10 November 1992. These systems formed part of the first generation of systems based on the 64-bit
Alpha AXP architecture and at the time of introduction, ran Digital's OpenVMS AXP
or OSF/1 AXP operating systems
.
The DEC 4000 AXP was succeeded by the end of 1994 by the AlphaServer
2000 and 2100 departmental servers.
The possible values of 'x' is 1 or 2. These numbers specify the number of microprocessors in the system.
(SMP) capable systems that are housed in either a BA640 half-height cabinet or a BA641 19-inch rackmountable enclosure that contains two backplane
s, a system backplane and a storage backplane. Plugged in the system backplane were one or two CPU modules, one to four memory modules, an I/O
module, up to six Futurebus+ Profile B
modules, and in the storage backplane, were one to four fixed media mass storage compartments and one removable media mass storage compartment.
microprocessor
with 1 MB of B-cache (L2 cache
), whereas the B2012-AA contains a 190 MHz DECchip 21064 with 4 MB of B-cache. Two C3 (Command, Control and Communication) ASIC
s on the CPU module provide a number of functions, such as implementing the B-cache controller and the bus interface unit (BIU), which interfaces the microprocessor to the 128-bit address
and data multiplexed system bus to enable communication between the CPU, memory and I/O modules. These ASICs were fabricated in a 0.8 micrometre process.
The memory is implemented using 280 surface mounted
dual in-line package
(DIP) 4-bit dynamic random access memory
(DRAM) chips with capacities of 1, 4 and 16 Mb that reside on both sides of the module.
Located on the module are two CMIC ASICs which control the memory and interface the module to the system bus. Each CMIC ASIC is responsible for managing half of the 280-bit memory bus and the 128-bit system bus. The CMIC ASICs are fabricated in a CMOS process and are packaged in a 299-position pin grid array
(PGA) package.
The memory module is the same size as the CPU module and connects to the backplane via two 129-pin and four 24-pin connectors.
buses and two Ethernet
ports and the second variant offered four DSSI
/SCSI buses and one Ethernet port. The second variant however only has half the bandwidth of the SCSI-2 buses of the first variant, although the advanced features of DSSI justified its use in some cases. Aside from these differences, the rest of the I/O module was essentially the same.
I/O module features common to both variants are an additional SCSI-2 bus for removable media drives only, a Zilog
85C30 Serial Communications Controller (UART) that provides two serial lines
, a Dallas Semiconductor
DS1287 real time clock, and most of the firmware in the DEC 4000 AXP. For controlling the Futurebus+ and to interface the I/O module to the system bus, two IONIC ASICs are used. The Ethernet functionality in the I/O function is provided by the TGEC (Third Generation Ethernet Chip), also known as the DC253, while the SCSI/DSSI buses are provided by four NCR 53C710
SCSI/DSSI controllers and their associated DSSI drivers (second I/O module variant only).
Most of the I/O devices are connected to the local I/O bus, known as the "Lbus", a 32-bit address and data multiplexed bus.
Server (computing)
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
developed and manufactured by Digital Equipment Corporation
Digital Equipment Corporation
Digital Equipment Corporation was a major American company in the computer industry and a leading vendor of computer systems, software and peripherals from the 1960s to the 1990s...
introduced on 10 November 1992. These systems formed part of the first generation of systems based on the 64-bit
64-bit
64-bit is a word size that defines certain classes of computer architecture, buses, memory and CPUs, and by extension the software that runs on them. 64-bit CPUs have existed in supercomputers since the 1970s and in RISC-based workstations and servers since the early 1990s...
Alpha AXP architecture and at the time of introduction, ran Digital's OpenVMS AXP
OpenVMS
OpenVMS , previously known as VAX-11/VMS, VAX/VMS or VMS, is a computer server operating system that runs on VAX, Alpha and Itanium-based families of computers. Contrary to what its name suggests, OpenVMS is not open source software; however, the source listings are available for purchase...
or OSF/1 AXP operating systems
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
.
The DEC 4000 AXP was succeeded by the end of 1994 by the AlphaServer
AlphaServer
AlphaServer was the name given to a series of server computers, produced from 1994 onwards by Digital Equipment Corporation, and latterly by Compaq and HP. As the name suggests, the AlphaServers were based on the DEC Alpha 64-bit microprocessor...
2000 and 2100 departmental servers.
Models
There are two models of the DEC 4000 AXP:- Model 6x0, code named Cobra: 160 MHz DECchip 21064Alpha 21064The Alpha 21064 is a microprocessor developed and fabricated by Digital Equipment Corporation that implemented the Alpha instruction set architecture . It was introduced as the DECchip 21064 before it was renamed in 1994. The 21064 is also known by its code name, EV4...
(EV4) processor(s) with 1 MB L2 cache each. - Model 7x0, code named Fang: 190 MHz DECchip 21064 (EV4) processor(s) with 4 MB L2 cache each. It was introduced in October 1993.
The possible values of 'x' is 1 or 2. These numbers specify the number of microprocessors in the system.
Description
The DEC 4000 AXP are two-way symmetric multiprocessingSymmetric multiprocessing
In computing, symmetric multiprocessing involves a multiprocessor computer hardware architecture where two or more identical processors are connected to a single shared main memory and are controlled by a single OS instance. Most common multiprocessor systems today use an SMP architecture...
(SMP) capable systems that are housed in either a BA640 half-height cabinet or a BA641 19-inch rackmountable enclosure that contains two backplane
Backplane
A backplane is a group of connectors connected in parallel with each other, so that each pin of each connector is linked to the same relative pin of all the other connectors forming a computer bus. It is used as a backbone to connect several printed circuit boards together to make up a complete...
s, a system backplane and a storage backplane. Plugged in the system backplane were one or two CPU modules, one to four memory modules, an I/O
Input/output
In computing, input/output, or I/O, refers to the communication between an information processing system , and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it...
module, up to six Futurebus+ Profile B
Futurebus
Futurebus is a computer bus standard, intended to replace all local bus connections in a computer, including the CPU, memory, plug-in cards and even, to some extent, LAN links between machines. The effort started in 1979 and didn't complete until 1987, and then immediately went into a redesign...
modules, and in the storage backplane, were one to four fixed media mass storage compartments and one removable media mass storage compartment.
CPU module
Two models of CPU module were used in the DEC 4000 AXP, the KN430 (also known as the B2001-BA), used in the Model 600 Series, and the B2012-AA, used in the Model 700 Series. The KN430 contains a 160 MHz DECchip 21064Alpha 21064
The Alpha 21064 is a microprocessor developed and fabricated by Digital Equipment Corporation that implemented the Alpha instruction set architecture . It was introduced as the DECchip 21064 before it was renamed in 1994. The 21064 is also known by its code name, EV4...
microprocessor
Microprocessor
A microprocessor incorporates the functions of a computer's central processing unit on a single integrated circuit, or at most a few integrated circuits. It is a multipurpose, programmable device that accepts digital data as input, processes it according to instructions stored in its memory, and...
with 1 MB of B-cache (L2 cache
CPU cache
A CPU cache is a cache used by the central processing unit of a computer to reduce the average time to access memory. The cache is a smaller, faster memory which stores copies of the data from the most frequently used main memory locations...
), whereas the B2012-AA contains a 190 MHz DECchip 21064 with 4 MB of B-cache. Two C3 (Command, Control and Communication) ASIC
Application-specific integrated circuit
An application-specific integrated circuit is an integrated circuit customized for a particular use, rather than intended for general-purpose use. For example, a chip designed solely to run a cell phone is an ASIC...
s on the CPU module provide a number of functions, such as implementing the B-cache controller and the bus interface unit (BIU), which interfaces the microprocessor to the 128-bit address
Address bus
An address bus is a computer bus that is used to specify a physical address. When a processor or DMA-enabled device needs to read or write to a memory location, it specifies that memory location on the address bus...
and data multiplexed system bus to enable communication between the CPU, memory and I/O modules. These ASICs were fabricated in a 0.8 micrometre process.
Memory module
The MS430 memory module has capacities of 32, 64, 128, 256 and 512 MB of memory. The memory is organised into four banks, each 280 bits wide, of which 256 bits are used to store data and 24 bits are used to store error detection and correction (EDC) information. The memory is protected by EDC logic, which is capable of detecting and correcting 1-bit errors and common 2-, 3- and 4-bit errors.The memory is implemented using 280 surface mounted
Surface-mount technology
Surface mount technology is a method for constructing electronic circuits in which the components are mounted directly onto the surface of printed circuit boards . An electronic device so made is called a surface mount device...
dual in-line package
Dual in-line package
In microelectronics, a dual in-line package is an electronic device package with a rectangular housing and two parallel rows of electrical connecting pins. The package may be through-hole mounted to a printed circuit board or inserted in a socket.A DIP is usually referred to as a DIPn, where n is...
(DIP) 4-bit dynamic random access memory
Dynamic random access memory
Dynamic random-access memory is a type of random-access memory that stores each bit of data in a separate capacitor within an integrated circuit. The capacitor can be either charged or discharged; these two states are taken to represent the two values of a bit, conventionally called 0 and 1...
(DRAM) chips with capacities of 1, 4 and 16 Mb that reside on both sides of the module.
Located on the module are two CMIC ASICs which control the memory and interface the module to the system bus. Each CMIC ASIC is responsible for managing half of the 280-bit memory bus and the 128-bit system bus. The CMIC ASICs are fabricated in a CMOS process and are packaged in a 299-position pin grid array
Pin grid array
A pin grid array, often abbreviated PGA, is a type of integrated circuit packaging. In a PGA, the package is square or roughly square, and the pins are arranged in a regular array on the underside of the package...
(PGA) package.
The memory module is the same size as the CPU module and connects to the backplane via two 129-pin and four 24-pin connectors.
I/O module
The DEC 4000 AXP uses the KFA40 I/O module, which contains the entire I/O subsystem. The I/O module is the largest module in the system, and two variants existed. The first variant offered four SCSI-2SCSI
Small Computer System Interface is a set of standards for physically connecting and transferring data between computers and peripheral devices. The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI is most commonly used for hard disks and tape drives, but it...
buses and two Ethernet
Ethernet
Ethernet is a family of computer networking technologies for local area networks commercially introduced in 1980. Standardized in IEEE 802.3, Ethernet has largely replaced competing wired LAN technologies....
ports and the second variant offered four DSSI
Digital Storage Systems Interconnect
The Digital Storage Systems Interconnect is a bus developed by Digital Equipment Corporation for connecting storage devices and clustering VAX systems and support was extended to MIPS based DECsystem and later to Alpha processor based AlphaServer systems.It was introduced in 1988 and has a...
/SCSI buses and one Ethernet port. The second variant however only has half the bandwidth of the SCSI-2 buses of the first variant, although the advanced features of DSSI justified its use in some cases. Aside from these differences, the rest of the I/O module was essentially the same.
I/O module features common to both variants are an additional SCSI-2 bus for removable media drives only, a Zilog
Zilog
Zilog, Inc., previously known as ZiLOG , is a manufacturer of 8-bit and 24-bit microcontrollers, and is most famous for its Intel 8080-compatible Z80 series.-History:...
85C30 Serial Communications Controller (UART) that provides two serial lines
Serial port
In computing, a serial port is a serial communication physical interface through which information transfers in or out one bit at a time...
, a Dallas Semiconductor
Dallas Semiconductor
Dallas Semiconductor, now a subsidiary of Maxim Integrated Products, designs and manufactures analog, digital, and mixed-signal semiconductors...
DS1287 real time clock, and most of the firmware in the DEC 4000 AXP. For controlling the Futurebus+ and to interface the I/O module to the system bus, two IONIC ASICs are used. The Ethernet functionality in the I/O function is provided by the TGEC (Third Generation Ethernet Chip), also known as the DC253, while the SCSI/DSSI buses are provided by four NCR 53C710
NCR Corporation
NCR Corporation is an American technology company specializing in kiosk products for the retail, financial, travel, healthcare, food service, entertainment, gaming and public sector industries. Its main products are self-service kiosks, point-of-sale terminals, automated teller machines, check...
SCSI/DSSI controllers and their associated DSSI drivers (second I/O module variant only).
Most of the I/O devices are connected to the local I/O bus, known as the "Lbus", a 32-bit address and data multiplexed bus.