DEC 3000 AXP
Encyclopedia
DEC 3000 AXP was the name given to a series of computer workstations and servers, produced from 1992 to around 1995 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...

. The DEC 3000 AXP series formed part of the first generation of computer systems based on the 64-bit Alpha AXP architecture. Supported operating systems for the DEC 3000 AXP series were DEC OSF/1 AXP (later renamed Digital UNIX) and OpenVMS AXP (later renamed OpenVMS
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...

).

All DEC 3000 AXP models used the DECchip 21064
Alpha 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...

 (EV4) or DECchip 21064A
Alpha 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...

 (EV45) processor and inherited various features from the earlier MIPS architecture
MIPS architecture
MIPS is a reduced instruction set computer instruction set architecture developed by MIPS Technologies . The early MIPS architectures were 32-bit, and later versions were 64-bit...

-based DECstation
DECstation
The DECstation was a brand of computers used by DEC, and refers to three distinct lines of computer systems—the first released in 1978 as a word processing system, and the latter two both released in 1989. These comprised a range of computer workstations based on the MIPS architecture and a...

 models, such as the TURBOchannel
TURBOchannel
TURBOchannel is an open computer bus developed by DEC by during the late 1980s and early 1990s. Although it was open for any vendor to implement in their own systems, it was mostly used in Digital's own systems such as the MIPS-based DECstation and DECsystem systems, in the VAXstation 4000, and in...

 bus and the I/O subsystem.

The DEC 3000 AXP series was superseded in late 1994, with workstation models replaced by the AlphaStation
AlphaStation
AlphaStation was the name given to a series of computer workstations, produced from 1994 onwards by Digital Equipment Corporation, and latterly by Compaq and HP. As the name suggests, the AlphaStations were based on the DEC Alpha 64-bit microprocessor...

 line and server models replaced 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...

 line.

Models

There were three DEC 3000 model families, codenamed Pelican
Pelican
A pelican, derived from the Greek word πελεκυς pelekys is a large water bird with a large throat pouch, belonging to the bird family Pelecanidae....

, Sandpiper, and Flamingo
Flamingo
Flamingos or flamingoes are gregarious wading birds in the genus Phoenicopterus , the only genus in the family Phoenicopteridae...

. Within Digital, this led to the DEC 3000 series being affectionately referred to as "the seabirds".
Model Codename CPU CPU MHz B-cache (L2) Chassis Introduced Withdrawn
Model 300 Pelican EV4 150 256 KB Desktop 1993-04-20 ?
Model 300L Pelica EV4 100 256 KB Desktop 1993-04-20 1994-03-25
Model 300X Pelican+ EV4 175 256 KB Desktop 1994-02-08 1995-10-02
Model 300LX Pelica+ EV4 125 256 KB Desktop 1994-02-08 1995-06-23
Model 400 Sandpiper EV4 133 512 KB Desktop 1992-11-10 ?
Model 500 Flamingo EV4 150 512 KB Pedestal 1992-11-10 ?
Model 500X Hot Pink EV4 200 512 KB Pedestal 1993-04-20 ?
Model 600 Sandpiper+ EV4 175 2 MB Desktop 1993-10-13 1995-10-02
Model 700 Sandpiper45 EV45 225 2 MB Desktop 1994-07-21 1995-10-02
Model 800 Flamingo II EV4 200 2 MB Pedestal 1993-10-13 1994-02-12
Model 900 Flamingo 45 EV45 275 2 MB Pedestal 1994-07-21 1995-10-02


Note: Server configurations of the Model 400/500/600/700/800/900 systems were suffixed with "S".

Description

The logic in Flamingo- and Sandpiper-based systems are contained on two modules (printed circuit boards), the CPU module and the I/O module, with the CPU module being the largest board. The two modules are connected via a 210-pin connector. The logic in Pelican-based systems are contained the CPU module and system module. The CPU module is a daughterboard that plugs into the system module and contains the CPU and the B-cache (L2 cache).

The architecture of the Flamingo- and Sandpiper-based systems is based around a crossbar switch
Crossbar switch
In electronics, a crossbar switch is a switch connecting multiple inputs to multiple outputs in a matrix manner....

 implemented by a ADDR (Address) ASIC, four SLICE (data slice) ASICs and a TC (TURBOchannel) ASIC. These ASICs connect together the various different width buses used in the system, allowing data to be transferred to the different subsystems. PAL
Programmable Array Logic
The term Programmable Array Logic is used to describe a family of programmable logic device semiconductors used to implement logic functions in digital circuits introduced by Monolithic Memories, Inc. in March 1978. MMI obtained a registered trademark on the term PAL for use in "Programmable...

s were used to implement the control logic. The cache, memory and TURBOchannel controllers, as well as other control logic, is entirely implemented by PALs. Pelican-based systems have an entirely different architecture from the other systems, similar to that of late-model Personal DECstations
DECstation
The DECstation was a brand of computers used by DEC, and refers to three distinct lines of computer systems—the first released in 1978 as a word processing system, and the latter two both released in 1989. These comprised a range of computer workstations based on the MIPS architecture and a...

 that they are based on, with a traditional workstation architecture with buses and buffers.

Memory

The Sandpiper and Flamingo used proprietary 100-pin, 40-bit (32 bits plus 8 bits ECC) Fast Page Mode SIMM
SIMM
A SIMM, or single in-line memory module, is a type of memory module containing random access memory used in computers from the early 1980s to the late 1990s. It differs from a dual in-line memory module , the most predominant form of memory module today, in that the contacts on a SIMM are redundant...

s with capacities of 2 MB, 4 MB, 8 MB, 16 MB or 32 MB. These were eight-way interleaved, providing a 256-bit-wide bus to memory. The Sandpiper had two such eight-SIMM banks, for up to 512 MB total system RAM, while the Flamingo had four banks and supported up to 1 GB. In comparison, the Pelican was a budget architecture utilising eight standard 72-pin Fast Page Mode SIMMs that were protected with longword parity instead of ECC, with capacities of 8 MB or 32 MB, for a total of up to 256 MB RAM. These were two-way interleaved, for a 64-bit-wide bus to memory.

Expansion slots

The DEC 3000 AXP series uses the 32-bit TURBOchannel
TURBOchannel
TURBOchannel is an open computer bus developed by DEC by during the late 1980s and early 1990s. Although it was open for any vendor to implement in their own systems, it was mostly used in Digital's own systems such as the MIPS-based DECstation and DECsystem systems, in the VAXstation 4000, and in...

 bus running at various speeds, 12.5 MHz in the 300 models, 22.5 MHz in the 400 models and 25 MHz in models 500 to 900. The TURBOchannel bus is provided by an ASIC
ASIC
ASIC may refer to:* Application-specific integrated circuit, an integrated circuit developed for a particular use, as opposed to a customised general-purpose device.* ASIC programming language, a dialect of BASIC...

, which connected it to the SLICE data path ASICs. The number to expansion slots also varied, the 300 models had two slots, except for the 300L, which had none. Models 400, 600 and 700 had three slots, the model 500X featured five, while models 500, 700 and 800 featured six.

Graphics

The Model 300 Series and the Model 500, 500S and 500X feature integrated graphics provided by the CXTurbo subsystem, which resides on the system module. This subsystem is essentially an onboard HX TURBOchannel option module. The subsystem features a SFB (Smart Frame Buffer) ASIC, a Brooktree
Brooktree
Brooktree is an American company founded in 1983 by Henry Katzenstein to commercialize a faster hardware architecture for digital to analog converters, three to eight times faster than the converters on the market....

 Bt459 RAMDAC
RAMDAC
Random Access Memory Digital-to-Analog Converter is a combination of three fast DACs with a small SRAM used in computer graphics display adapters to store the color palette and to generate the analog signals to drive a color monitor...

, 2 MB of VRAM
VRAM
Video RAM, or VRAM, is a dual-ported variant of dynamic RAM , which was once commonly used to store the framebuffer in some graphics adapters....

 and in the Model 500, 500S and 500X, a 256 KB flash
Flash memory
Flash memory is a non-volatile computer storage chip that can be electrically erased and reprogrammed. It was developed from EEPROM and must be erased in fairly large blocks before these can be rewritten with new data...

 ROM that holds part of the system firmware. The CXTurbo subsystem can reach resolutions of 1280 × 1024 at 72 Hz in the 300, 300X and 300LX models, 1024 × 768 at 72 Hz in the Model 300L and 1280 × 1024 at 66 Hz or 72 Hz in the Model 500, 500S and 500X.

Because of the DEC 3000 AXP's similarity with Digital's previous RISC workstation line, the DECstation
DECstation
The DECstation was a brand of computers used by DEC, and refers to three distinct lines of computer systems—the first released in 1978 as a word processing system, and the latter two both released in 1989. These comprised a range of computer workstations based on the MIPS architecture and a...

, the same TURBOchannel graphics options, which consisted of framebuffers, 2D and 3D accelerated graphics, were carried over the DEC 3000 AXP. Like the DECstation, up to three (the actual number may be less, depending on the number of TURBOchannel option slots the system features) framebuffers of the same model can be installed in a single system to support multiscreen configurations.

Despite using the same graphics options as the DECstation at introduction, later options for the DEC 3000 AXP were designed exclusively for the platform. These options were Digital's ZLX-E1/E2/E3, ZLX-L1/L2 and ZLX-M1/M2 series of PixelVision architecture-based 2D/3D accelerated graphics and Kubota's high-end 3D accelerated graphics subsystem, the Denali. The Denali is an external enclosure that contains up to six geometry engines and multiple memory modules. It was capable of advanced (for the time) 3D graphics, such as interactive volume rendering
Volume rendering
In scientific visualization and computer graphics, volume rendering is a set of techniques used to display a 2D projection of a 3D discretely sampled data set.A typical 3D data set is a group of 2D slice images acquired by aCT, MRI, or MicroCT scanner....

. It connects to the DEC 3000 AXP via a cable and a TURBOchannel interface module.

I/O subsystem

The I/O subsystem provides the DEC 3000 AXP with 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....

, ISDN and audio capability, four serial lines, and a real time clock. The I/O subsystem is interfaced to TURBOchannel by the IOCTL ASIC, which also implements two 8-bit buses, known as IOBUS HI and IOBUS LO, to which the I/O devices connect to. These two 8-bit buses can be combined to serve as one 16-bit bus to provide an I/O device with more bandwidth. Ethernet is provided by an AMD Am7990 LANCE
AMD Lance Am7990
AMD Lance Am7990 IEEE 802.3 Ethernet Media Access Controller controller were introduced in 1985. Its architecture is the basis for AMD’s PCnet Family of highly integrated single-chip Ethernet controllers...

 (Local Area Network Controller for Ethernet), an AMD Am7992 SIA (Serial Interface Adapter) that implements the 10BASE-T or AUI Ethernet interface, and an ESAR (Ethernet Station Address ROM) that stores the MAC address. The Am7990 is the only I/O device in the subsystem to have a 16-bit interface to the IOCTL ASIC. ISDN and telephone-quality audio is provided by an AMD Am79C30A DSC (Digital Subscriber Controller). The four serial lines are provided by two 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:...

 Z85C30 SCC (Serial Communications Controller) dual UARTs, and the real time clock is a Dallas Semiconductor
Dallas Semiconductor
Dallas Semiconductor, now a subsidiary of Maxim Integrated Products, designs and manufactures analog, digital, and mixed-signal semiconductors...

 DS1287A.

SCSI interface

The DEC 3000 AXP used a TCDS (TURBOchannel Dual SCSI) ASIC to provide an interface between the SCSI
SCSI
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...

 controllers and the TURBOchannel bus. Early systems used one (Model 300s) or two (Model 400 and 500) NCR
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...

 53C94
NCR 53C9x
The NCR 53C9x is a family of application-specific integrated circuits produced by the former NCR Corporation for implementing the SCSI protocol in hardware. The 53C9x is a low-cost solution and was therefore widely adopted by OEMs in various motherboard and peripheral device designs...

SCSI controllers, which provided one or two 5 MB/s 8-bit single ended SCSI buses. Later and higher end systems such as the Model 600, 700, 800 and 900 also feature two SCSI controllers, but used the NCR 53CF94-2 instead, which provided faster 10 MB/s 8-bit single ended SCSI buses.

External links

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