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1992-09-13
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WELCOME TO THE WORLD OF ALPHA -- A NEW FUTURE BEGINS
Digital is introducing the Alpha (Digital's internal code name)
architecture, the world's fastest microprocessor, and new open business
practices for licensing and selling Alpha technology. Digital has a clear
vision for the future of computing and a consistent product strategy based
on leadership in open systems. Digital products are your best investment in
a secure future.
What is Alpha? Alpha is a totally new, open computer architecture that
positions Digital as an industry leader for the rest of the decade and into
the next century. Alpha goes well beyond current computing environments to
cover multiple operating systems, desktops, supercomputers, embedded
realtime, LAN products, and more.
This announcement includes these key items:
o Digital has developed the Alpha architecture specifically to be fast,
scalable, open, widely useful, and enduring.
o Digital's first Alpha product is the world's first 64-bit, super-
pipelined, superscalar RISC microprocessor. This microprocessor is the
industry's fastest, supports the largest address space, and has the
widest data pipeline.
o In line with Digital's commitment to open business practices and open
systems, Digital will license the Alpha architecture and sell Alpha
technology at all levels of integration, making it widely available in
the industry. Thus Alpha technology will be available in implementations
ranging from embedded products to the world's most powerful
supercomputers.
Digital welcomes Kubota Corporation and Cray Research as its first system
partners developing and selling Alpha systems to complement Digital's
system products. More information on these partnerships and products will
be made available in the coming months.
o By the end of 1992, Digital will offer you Alpha systems from the desktop
to the datacenter, and these systems will be supported initially by both
the VMS and OSF/1 operating systems. These operating systems will be
available to other vendors selling Alpha systems.
Alpha systems complement and supplement today's products. They will coexist
with current and new generations of VAX systems and MIPS-based DECstation
systems, which will be introduced for years to come. Today's VAX and
DECstation products mean leadership in their own right, and now, with Alpha
coming, they also have the best future built in.
Alpha is an exciting new direction for Digital. The long-term objective is
to make Alpha the de facto industry standard for 64-bit computing. You will
be able to buy and use Digital's current products with the knowledge that
you can move to Alpha as your needs require.
Please contact your local Digital sales office for more information.
__________
OSF/1 is a registered trademark of the Open Software Foundation, Inc.
ALPHA: DELIVERING THE OPEN ADVANTAGE
HIGHLIGHTS
o Alpha means leadership, translating into low-cost solutions for your
business needs
o Alpha provides an open-ended growth opportunity for your present computer
installations
o Alpha delivers the Open Advantage, the standard of comparison for open
computing
The Alpha program positions Digital at the forefront of the computer
industry through the rest of the decade and into the 21st century. Today,
Digital is introducing entirely new business practices and a new technology
base (Alpha). Alpha is the ultimate proof point of Digital's claim to the
Open Advantage.
The real excitement of Alpha is the software technology Digital is
delivering. This will enable you to move smoothly to integrate the new
leadership RISC hardware and leapfrog the competition in performance, while
protecting your investments in software, applications, data, and business
information. This level of compatibility is unprecedented in any
introduction of RISC technology.
ALPHA MEANS LEADERSHIP
Alpha differentiates Digital from every other vendor. Future leaders of the
computer industry will need five core competencies to keep their competitive
edge. Digital has them now:
o Computer architecture and systems design
o Microprocessor design and fabrication
o Software: operating systems, compilers, and "middleware"
o Financial staying power
o Worldwide service and support
Alpha's features make it more advanced than existing computer architectures:
o Fast 64-bit RISC on a single chip
o Unbiased toward any operating system or language
o Upward scalable by 1000 times over the initial performance
o Single processor to massively parallel processors
o Designed to be openly licensed and sold
These architectural features translate into low-cost, high-performance,
low-risk, and more enduring solutions for you.
Alpha with the VMS, OSF/1, and other operating systems opens new
opportunities:
o "Right sizing" the mainframe
o Technical hot-box applications
o New high-performance, personal-use applications
o Embedded applications through OEMs
o New services for end users and partners
ALPHA PROVIDES A GROWTH PATH
Alpha systems will provide a high-end growth path for all the Digital
products you are using today. The unprecedented level of software
compatibility means that current ULTRIX and VMS applications have an assured
future running on the highest performance, open systems platforms. And you
can build the innovative applications of tomorrow on today's products and be
assured of smooth deployment on Alpha systems.
Digital's open business practices, combined with leadership Alpha
technology and service, provide a compelling vision of Digital's ability to
support your growing business needs. Your investments in Digital's products
and long-term strategy will be secure.
ALPHA DELIVERS THE OPEN ADVANTAGE
Digital's Open Advantage promises you the freedom to choose and the power to
use the best applications available while optimizing your current and future
investments. Alpha was designed to deliver on this promise.
Alhha Open Technology
o A totally new, open, 64-bit RISC computing architecture
o A single-chip implementation of the archture -- the world's fastest
microprocessor
o A family of systems and software spanning the desktop to the datacenter
using the OSF/1 and VMS operating systems
Alpha is a new computing architecture, designed from the outset to be open
and fast. Unlike other RISC architectures, Alpha is not biased toward any
operating system or language. This means Alpha systems can be equally good
at supporting OSF/1, VMS, and other operating s stems. This is an important
and unique feature of Alpha -- the choice of operating environment. For
example, if you currently the VMS operating system on VAX systems, you
can introduce leading performance Alpha systems that not only coexist but
run the same operating environment. This gives you a wider choice in how to
use Alpha technology to best solve your business problems.
The Alpha chip is the world's fastest microprocessor -- and this is just the
first Digital implementation. Digital has achieved a sustainable improvement
in microprocessor performance through the inherent nature of the Alpha
architecture, including the use of multiple instruction issue,
superpipelining, unique compilers, and Digital's leadership CMOS design and
fabrication capability.
Alpha is also designed to be open to partners -- easy to build into systems
and embedded applications that you can use.
Alpha Open Business Practices
o New forms of partner ng with semiconductor companies, computer system
houses, and embedded application vendors
o Alpha technology available at levels of integration -- chips, boards,
and systems
o A balanced approach to operating system support
o A portfolio of applications
o Licensing of Digital software for use by partners who build and sell
Alpha systems
In an unprecedented open approach, Digital will license the Alpha
architecture to one or more semiconductor companies. These architectural
partners will help Alpha chips become widely available in products you will
want to acquire. Digital is partnering with system houses -- other computer
companies -- who want to build systems using the Alpha architecture.
Alpha was designed from the beginning to be open, with the ability to run
any operating system. At the outset, Digital will provide balanced support
for the OSF/1 and VMS operating systems. Other operating systems will be
added to address new user needs.
Over time, Alpha will have the broadest and deepest portfolio of
applications ever available on a Digital platform. The company is under-
taking an unprecedented support program to help third-party vendors move
their applications to Alpha.
Consistent with the architectural licensing and sale of chips and boards,
Digital will license its operating systems, compilers, and layered products
on Digital and non-Digital Alpha systems. This is confirmation of Digital's
commitment as an open software vendor.
Alpha Open Services
o End User Services and Vendor Services to support Alpha
o Application Migration Centers to help with planning and transition
Digital Services will support Alpha with two major categories of service --
End User Services for new and existing Digital users and Vendor Services for
vendors who use the Alpha technology in their products.
End User Services will focus on three main areas: Consulting Services,
Migration Services, and Educational and Training Services. These services
are designed to assist end users in the successful planning, design,
implementation, and management of a new Alpha environment.
Vendor Services will be offered to vendors who buy Alpha chips and
incorporate them in their own products.
New Application Migration Centers will help you plan for an orderly
transition from your current environment to a new, Alpha-based environment.
The article in this issue entitled "Digital Services Programs for Alpha"
provides detail on all these services.
Please contact your local Digital sales office for more information.
__________
OSF/1 is a registered trademark of the Open Software Foundation, Inc.
MEETING YOUR NEEDS WITH ALPHA
HIGHLIGHTS
o There will be a phased implementation of Alpha in Digital hardware,
software, and services
o Alpha will coexist with current VAX system and DECstation products
o Alpha will meet your needs across the range of Digital's offerings,
including systems, embedded hardware, software, services, and
applications
PHASED IMPLEMENTATION
Digital's initial family of systems, a number of products ranging from the
desktop to the datacenter, will be available in late 1992. These products
will be delivered with a choice of the OSF/1 or VMS operating system from
Digital.
ALPHA COMPLEMENTS CURRENT PRODUCTS
Alpha complements and extends Digital's VAX and DECstation products. Alpha
is not a replacement for today's products -- Alpha systems will coexist with
them. The current product families represent leadership in the industry.
They will be enhanced, sold, and supported for years to come.
Alpha systems can be added in the future to an existing DECsystem OSF/1 or
VAX VMS environment. This is possible because Alpha will be software
compatible with today's products, including full support of NAS software and
packages on toth the VMS and OSF/1 operating systems on Alpha. You can buy
current products confidently and invest in OSF/1 and VMS applicat
knowing that Alpha systems can be introduced in the future into those
environments without disruption.
EMBEDDED HARDWARE
Digital's open business practices include the licensing and sale of Alpha
technology at all levels of integration, including chips, single-board
computers, and systems.
This provides new opportunities for users who build computers or components
into their own products in a wide range of industries, including office
equipment, telecommunications, process control, energy management, medical
imaging, military electronics, automated test equipment, and many others.
SERVICES
Both direct end users and third-party vendors who incorporate Alpha -- from
chips through computer systems -- into their products will benefit from the
relevant Digital services available. These products can be computer or
noncomputer products. Users could include independent software vendors
integrating Alpha computer products, vendors withesoftware applications
running on Alpha systeand end user enterprises planning for Alpha
technology in the near and long term.
APPLICATIONS
Alpha systems will be used for applications that are currently in use, as
well as in the next generation of high-impact applications that are
beginning to emerge.
New High-Impact Applications
The high performance of RISC microprocessors, the high I/O bandwidth
provided by new system buses, and new distributed computing technologies are
converging to facilitate development of the next generation of user
interfaces and applications. These will offer high-impact benefits and
competitive advantages for Digital users. Examples include:
o Advanced user interfaces using voice I/O, video, multimedia, etc.
o Application visualization systems for technical and business
applications
o Virtual reality, for both entertainment and training applications
o Biological system simulation and modeling for development of
pharmaceuticals
o Econometric forecasting
o Extremely large database search and retrieval
Digital believes that because of performance and openness, Alpha will become
the platform of choice for development and deployment of these leading-edge
applications.
Existing Supercomputer and Other Applications
The increased performance of Alpha systems will provide an opportunity to
make high-performance technical computing applications available to more
users than was previously possible. Applications that typically ran on
supercomputers or large mainframes can be run very cost effectively on Alpha
systems; examples include:
o Seismic data analysis
o Computational chemistry
o Signal processing
o Computational physics
o Econometric forecasting
o Molecular modeling
o Weather forecasting
o Nonlinear finite element analysis
o Materials engineering
Other applications do not require supercomputer performance, but their
widespread implementation has been impeded by the cost of hardware required
to run them effectively. The price/performance of Alpha systems will make
these applications more widely affordable; examples include:
o Finite scheduling and simulation of manufacturing operations
o Complex distribution and logistics optimization
Please contact your local Digital sales office for more information.
__________
OSF/1 is a registered trademark of the Open Software Foundation, Inc.
ALPHA MAKES VAX VMS INVESTMENTS MORE VALUABLE
HIGHLIGHTS
o VAX VMS systems -- the best business critical solutions today now have
the best future built in
INTRODUCTION
If you are considering implementing new information technology, you are
quite possibly looking closely at the new Alpha technology and architecture.
You also want to make sure that the investments you make today will solve
today's business problems without compromising the ability to use tomorrow's
new breakthrough performance.
On October 30, 1991, Digital announced VAX systems that allowed you to
implement business solutions without compromise. VMS software had
established a well recognized leadership position for functionality, but
with price/performance being the best in the industry (TPC-A data) and with
open multivendor computing through POSIX, Motif, and the rest of NAS, VMS
software became the clear choice for computing. You could have it all:
functionality, price/performance, and open systems, without compromise.
With Alpha running VMS software, you have an additional opportunity for the
future: You can deploy on leadership VAX VMS systems now with the assurance
that your environment will be leadership for decades to come.
VMS INTO THE FUTURE
Alpha provides the computing platform that ensures VMS software will be the
leader in business critical, "no compromise" computing for decades to come.
VMS software running on Alpha marries the most advanced computing
architecture (Alpha) with a software environment that has the data integrity
and capacily to handle large business critical solutions. This environment
is unrivaled in terms of availability features, openness, and lost.
VMS software on the Alpha platform has the potential to provide the
necessary performance and functionality for business critical solutions that
in the past required mainframes or could not be done on any computer. VMS
software for Alpha will also enable the creation of new business critical
solutions. Consider the advantages you will have in downsizing to a
radically lower cost solution without giving up performance or losing
functionality!
VMS software for Alpha will allow these business critical applications to
harness the power-hungry technologies of the '90s: multimedia, imaging,
object oriented, artificial intelligence, global networks, and multivendor
computing.
VMS IS STILL VMS
New and different, Alpha opens up whole new worlds. But from a software
perspective, it is the same as your VAX syhtems -- it runs VMS software.
All of thfferent hardware platforms will work together because they all
run VMS software: yesterday's VAX systems, today's VAX systems, and
tomorrow's Alpha and VAX systems. All will coexist in the same network,
running the same applications, with the same user interface, using the same
data, sharing the same peripherals, used by the same trained VMS
knowledgeable people. Eventually, all will work together in the same
cluster configuration.
Thus, nearly all of your investment moves smoothly forward to Alpha.
The upcoming availability of Alpha actually enhances the value of VAX VMS
computing solutions today. VMS software for Alpha will easily accelerate
today's VAX VMS solutions to much higher performance levels. This potential
makes these solutions more valuable, going beyond mere investment protection
to investment enhancement.
You should also know that new, exciting VAX systems are coming in the
future. New VAX systems will be introduced for many years to come, offering
higher systems performance, reliability, and flexibility.
VMS LEADERSHIP TODAY
The VMS leadership story delivered with the new VAX systems on October 30,
1991, was clear and straightforward: "no compromise" computing for business
critical solutions, with best functionality, best open multivendor
computing, best performance, and best price/performance.
Functionality is of paramount importance for most business critical
solutions. VMS software offers exceptional data protection, thanks to
leadership dependability -- data integrity, availability, and security. VMS
software offers outstanding flexibility to scale solutions up from local to
global, based on the scalability of Digital's systems, I/O, networks, and
CASE tools. Digital supports VMS functionality with its capabilities as one
of the world's top three systems integrators, with over 40,000 service
professionals.
Open multivendor computing has become an integral part of VMS software,
which has gracefully made the transition from proprietary to open without
compromising functionality or performance. Support for POSIX, Motif, and
standards-based NAS makes the VMS operating system the premier open system.
The best performance and price/performance were easy to prove with the
audited TPC-A benchmarks published at announcement on October 30. These
benchmarks showed that the new VAX 4000 and VAX 6000 products were the world
leaders in their class. (For more information on these benchmarks, please
refer to the Special Issue, dated October 30, 1991, of Digital's Customer
Update.)
BUSINESS CRITICAL COMPUTING LEADERSHIP TOMORROW
New business critical solutions and solutions re-engineered from their
mainframe versions are now financially viable for migration consideration --
possibly for the first time for many sites. Digital products and services
will focus on this emerging new environment. You can begin to develop and
migrate today on VAX VMS systems, and when appropriate, deploy on Alpha
systems running VMS software.
Please contact your local Digital sales office for more information.
__________
Motif is a registered trademark of the Open Software Foundation, Inc.
USING UNIX TODAY AND TOMORROW
HIGHLIGHTS
o MIPS ULTRIX -- best RISC entry price and upgradability in the industry;
over 3000 ULTRIX applications available today; Digital has ACE-compatible
products today and future products under development
o DEC OSF/1 software for MIPS -- developers' platform for OSF/1 on MIPS
and/or Alpha; first OSF/1 offering in the industry from a major vendor
o DEC OSF/1 software will unite Digital's UNIX offerings, supporting MIPS
and Alpha and providing unequaled investment protection with coexistence,
compatibility, and migration opportunities
o Digital will have the industry's highest-performance UNIX platforms with
DEC OSF/1 software on Alpha
INTRODUCTION
If you are considering implementing new information technology, you are
quite possibly very impressed with the new Alpha technology and
architecture. You also want to make sure that the investments you make today
will solve today's business problems without compromising the ability to use
tomorrow's new breakthrough performance.
ULTRIX AND MIPS FOR TODAY'S APPLICATIONS
Digital is developing a series of MIPS R4000 daughter card upgrades, thereby
assuring MIPS users of long-term investment protection for their DECstation
and DECsystem purchases today. And with plans for MIPS multiprocessors in
the future, users will continue to have binary compatibility with MIPS from
desktop to datacenter. Existing ULTRIX applications will also be highly
portable to any future DEC OSF/1 system. You can indeed buy systems today
knowing the future performance you need is built in.
DEC OSF/1 FOR NEW APPLICATIONS
Digital has announced the availability of the first commercial version of
OSF/1 from a major vendor, on DECstation and DECsystem platforms (MIPS).
Independent software vendors have announced support for over 100
applications on the DEC OSF/1 platform.
DEC OSF/1 software provides a standards-compliant operating environment
that meets the needs of virtually all UNIX users. Most ULTRIX MIPS
applications can be moved in binary form to the DEC OSF/1 for MIPS
environment and run unmodified. If a new application is being created, DEC
OSF/1 V1.0 software for MIPS is the appropriate development vehicle, whether
you want to run the application on a MIPS and/or Alpha system. DEC OSF/1
software will continue to be available when Alpha systems start shipping.
Because Alpha will have the same OSF/1 implementation as MIPS, you can just
recompile and run the MIPS application on OSF/1 for Alpha. You can buy
inexpensive DECstation systems now to develop applications for use on Alpha.
DEC OSF/1 -- DIGITAL'S UNIX OPERATING SYSTEM
Digital's UNIX philosophy is based on a single OSF/1 implementation across
multiple architectures, including Intel, MIPS, and Alpha systems. Because
Digital will have one UNIX operating system (DEC OSF/1), it will be a simple
step to move applications from MIPS to Alpha by means of a simple recompile
and relink. Thus application portability and compatibility are assured, with
both MIPS and Alpha systems running DEC OSF/1 software able to work together
seamlessly in the same computing environment. For Intel platforms, the same
OSF/1 technology will be available in the future as part of the ACE
Initiative through Digital's partner, Santa Cruz Operations, Inc.
DEC OSF/1 software consolidates the major UNIX technology streams: BSD
(ULTRIX), System V, and OSF. The OSF/1 technology was developed by the Open
Software Foundation on Digital's DECstation products. Digital then built
into DEC OSF/1 software a high degree of ULTRIX binary compatibility. As a
result, you will benefit both in application portability and in protection
of your existing systems and applications investments, regardless of
underlying hardware.
HIGHEST-PERFORMANCE UNIX PLATFORMS WITH DEC OSF/1 ON ALPHA
With Alpha technology, Digital can deliver the industry's
highest-performance UNIX platforms. Digital will continue its OSF leadership
by introducing the first 64-bit operating system in the industry (see the
accompanying article entitled "DEC OSF/1 for Alpha").
Please contact your local Digital sales office for more information.
__________
OSF/1 is a registered trademark of the Open Software Foundation, Inc.
UNIX is a registered trademark of UNIX System Laboratories, Inc.
Intel is a trademark of Intel Corporation.
INDUSTRY LEADERSHIP INVESTMENT PROTECTION CONTINUES
HIGHLIGHTS
o Today's VAX and MIPS systems will work in a complementary way with
tomorrow's VAX and Alpha systems running VMS software and tomorrow's MIPS
and Alpha systems running OSF software
INVESTMENT PROTECTION PROGRAM
Seamless integration with other Digital platforms has been a design goal of
the Alpha program since its inception. Proof of the Alpha design success can
be found in:
o Data Compatibility: The VMS operating system on VAX and Alpha systems
will provide the same data formats, on-disk structures, file systems,
record management systems, and database systems. As a result, disks and
tapes can be moved back and forth between VAX and Alpha systems. Also,
VAX and Alpha systems will be able to share data on a common disk in a
VAXcluster configuration. Because MIPS and Alpha systems running OSF
provide the same data types, file systems, and database systems, disks
and tapes can be moved back and forth. And, of course, data can be moved
back and forth between systems via standard networking facilities.
This is a first in the industry; no other vendor has ever provided
complete data protection with the introduction of RISC technology.
o Source Code Compatibility: The VMS operating system on VAX and Alpha
systems will provide the same system services, runtime libraries (RTLs),
and POSIX interfaces. Thus, most VAX VMS programs (all nonprivileged
programs) will run on Alpha systems running VMS software, after a simple
recompile and relink. The same is true for OSF on MIPS and Alpha; the
same set of Application Programmer Interfaces (APIs) will be supported.
Almost all MIPS OSF programs will run on Alpha systems running OSF
software, after a recompile and relink.
Digital offers industry leadership software investment protection.
o Image Compatibility: Digital will provide a tool that allows most MIPS
OSF images to run on Alpha systems running OSF software, with Alpha
performance comparable to the then-current, high-performance MIPS
systems. Likewise, Digital will provide a tool that will allow most
nonprivileged VAX VMS images to run on Alpha systems running VMS
software, with performance comparable to that of then-current,
high-performance VAX systems.
o Applications Compatibility: Perhaps you depend heavily on one or more
third-party applications. Digital has been working for many months with
key application providers to ensure that users' applications will be
ready for the move to Alpha at the appropriate time.
o Common User Interfaces: Thanks to the way Alpha has been designed you
will find only one significant difference between the OSF operating
system on MIPS and Alpha systems, and between the VMS operating system on
VAX and Alpha systems: the performance of the Alpha systems will be much
higher. Common shells will be provided on MIPS and Alpha systems running
OSF software; DCL will be provided on VAX and Alpha systems running VMS
software. All systems will provide DECwindows and Motif software. No
retraining will be necessary, thereby increasing your productivity and
keeping costs down.
o Common NAS Middleware: Digital's leadership standards-based NAS software
will run on both VMS and OSF/1 software on Alpha. This not only provides
a common set of interfaces to simplify applications portability across
Alpha and VAX systems, but also provides data and application integration
across all existing and future NAS platforms.
o Common Peripherals: Alpha systems will support the TURBOchannel, XMI,
SCSI, DSSI, and Futurebus+ buses. VAX or MIPS peripherals that use those
buses can be moved to Alpha systems when the time is right for you.
Frequently, these peripherals are 50 percent or more of your systems
cost, so this feature is a major investment protection benefit.
Please contact your local Digital sales office for more information.
__________
Motif, OSF/1, and OSF are registered trademarks of the Open Software
Foundation, Inc.
ALPHA -- DIGITAL'S LEADERSHIP RISC ARCHITECTURE
HIGHLIGHTS
o Alpha is a new RISC architecture that is the first to provide features
that users are seeking today -- features that will pervade industry use
for generations to come; in short, Alpha is the first 21st century
computer architecture, offering:
- Leadership performance today and continuing tomorrow -- with a
performance increase of at least 1000 times designed into the Alpha
architecture
- Open performance architecture -- designed for widespread use
throughout the industry for many environments at all levels of
integration, from embedded to supercomputer
- Longevity -- Alpha's usefulness extends beyond most other computing
architectures selling today and it is the first to offer a
binary-compatible growth path into the 21st century
LEADERSHIP PERFORMANCE FOR TODAY AND TOMORROW
Alpha was specifically designed for high-speed, scalable implementations.
Many RISC design elements that could compromise performance (and do
compromise the performance of other RISC processors) were examined and new,
high-performance alternatives were developed for the Alpha architecture. The
Alpha RISC architecture is the best for optimizing performance along all
three major dimensions:
o Clock speed -- The simplicity of the design and Digital's outstanding
CMOS processor design and fabrication capability have made it possible to
deliver the fastest RISC microprocessor in the industry -- up to 200 MHz,
about two times the speed of the leading competitor.
o Multiple instruction issue -- Starting more instructions every clock
cycle improves performance (a lower number of cycles per instruction)
without the need for faster silicon. Alpha begins with a dual-issue
implementation (two instructions per cycle) and will expand this
capability beyond two.
o Multiple processors -- The Alpha architecture is the only leading RISC
architecture that has been designed from the outset to encourage
high-performance multiprocessor (and even massively parallel)
implementations. Alpha-based systems will have a significant advantage
over other RISC processors in multiprocessor implementations.
The combination of these three factors will allow Alpha systems to achieve
a performance increase of at least 1000 times over the life of the
architecture.
You can benefit from Alpha's continuing performance leadership, because it
can be translated either into new, leading applications using the Alpha
performance to your competitive advantage, or into maximum efficiency in
deploying your computing resources (using small, powerful Alpha systems for
functions formerly requiring much more expensive installations).
For more details on the Alpha architecture see the "Alpha Architecture
Technical Summary" article in this issue.
DESIGNED FOR OPEN SYSTEMS
The Alpha architecture is the first leading performance architecture to meet
the criteria for truly open industry use. This is based on two primary
factors:
o No bias towards a given operating system or programming language --
Initially Alpha systems will be able to run OSF/1 (UNIX) and VMS
operating systems. Not only is there no bias in the architecture towards
a particular operating system or programming language (such as UNIX or
C), but specific architectural features allow Alpha to be adapted to
different operating systems (see the PALcall instructions section in the
"Alpha Architecture Technical Summary" article).
o Single-chip implementation -- Having a single chip implementation opens
the door to leading embedded applications and compact systems (laptops,
palmtops), as well as allowing the broadest possible range of systems
families (mainframes, supercomputers, and massively parallel systems at
the high end).
The Alpha architecture is expected to be widely adopted in the industry.
This means that you will find compatible and complementary systems and
products from other vendors to amplify your application investments. It also
means that Alpha systems will retain not only performance leadership, but
price/performance leadership, as multiple vendors bring Alpha-based systems
to market.
THE FIRST 21ST CENTURY COMPUTER ARCHITECTURE
The Alpha architecture was designed for a 25-year design horizon. Digital
understands that you want to invest in complex applications technology
knowing that you will not have to change it five or even ten years later.
Alpha meets this need with a full 64-bit architecture.
Leading applications today (large system logic simulations and
verifications, for example) are already too large for 32-bit addressing
limits. Many new applications on the horizon will require a large address
space (multimedia, image processing). Over the course of the next few years
many of the industry's leading applications will move over the 32-bit limit.
All of the current 32-bit RISC architectures will be obsolete for these
applications.
Alpha users, by contrast, could invest in this architecture from the
beginning and run applications developed today on leading Alpha systems
throughout the entire Alpha life -- the same way today's VAX applications
can be run on the original VAX-11/780 systems. Because 64-bit addressing
allows for applications 4 billion times larger than those allowed by
32-bit addressing, this binary compatibility should have a very long life
indeed -- easily as long as the 25-year architectural design horizon.
In summary, the combination of leading qualities --
o Performance
o Openness and adaptability
o Longevity and compatibility
-- makes Alpha the first 21st century computing architecture.
Please contact your local Digital sales office for more information.
__________
OSF/1 is a registered trademark of the Open Software Foundation, Inc.
UNIX is a registered trademark of UNIX System Laboratories, Inc.
CMOS-4 CHIP MANUFACTURING TECHNOLOGY
HIGHLIGHTS
o Digital is a leading producer of high speed CMOS microprocessors
o Volume manufacturing of Alpha 21064-AA chips has begun in the U.S. and
will begin in Europe in May 1992
o Alpha chip technology offers:
- A minimum feature size of 0.75 micron
- A transistor channel length of 0.5 micron
- 3.3 V chip operation
- Unique features for very high microprocessor chip speed
TECHNOLOGY DESCRIPTION
CMOS-4 is the fourth generation of complementary metal oxide semiconductor
(CMOS) chip manufacturing technology developed by Digital's Semiconductor
Operations in Hudson, Massachusetts.
Each generation of CMOS technology is used to manufacture a wide range of
advanced chips used in computing hardware products. The focus of Digital's
CMOS technology that sets it apart from merchant semiconductor manufacturers
or vertically integrated systems competitors is that it is tuned to very-
high-speed complex logic functions with high-speed, on-chip memory.
World-leading microprocessor requirements matched with chip reliability
needs are used to pace and measure the manufacturing process development and
implementation.
Previous CMOS generations have delivered the world's fastest CISC
microprocessors in Digital's products. For example, in 1990 CMOS-3 delivered
a 62.5 MHz chip in the VAX 6000 Model 500 series. CMOS-4 has delivered an 83
MHz chip in the VAX 6000 Model 600 series. Digital is now using this same
technology to manufacture the Alpha CPU and a wide range of peripheral
chips.
CMOS-4 is at the leading edge of manufacturing processes in a number of
ways. The minimum patterned feature sizes in a chip are 0.75 micron and the
transistor electrical channel is 0.5 micron. These factors, coupled with
other unique applications of certain semiconductor materials, allow the
first Alpha chips to pack 1.68 million transistors with measured performance
at up to 200 MHz. Other features that allow CMOS-4 to produce world-leading,
very large scale integrated (VLSI) circuit chips include three levels of
interconnect metal (with very low third-level resistance), precision
resistors, local interconnect for dense RAM, low resistance grounding ring,
low resistance diffused silicon, and laser alterable metal fuses.
The production facilities in the U.S. and Europe operate at ultra-high
levels of purity and control, giving Digital best-in-class manufacturing
cycle times and product yields.
Please contact your local Digital sales office for more information.
ALPHA -- THE FASTEST MICROPROCESSOR
HIGHLIGHTS
o Digital announces the Alpha microprocessor (21064-AA), the first
chip-level implementation of the Alpha architecture
o The Alpha chip is the fastest CMOS microprocessor available in the world,
with a clock rate of up to 200 MHz
o This single-chip implementation of the Alpha architecture provides the
best RISC price/performance in the industry
OVERVIEW
Digital is announcing a new microprocessor that provides the best RISC
solution in the industry. The 21064-AA chip is the first in a family of
devices that will offer solutions at all levels of integration. The 21064-AA
microprocessor has a clock rate of up to 200 MHz and a superscalar
micro-architecture that dispatches up to two instructions per cycle.
CHIP DESCRIPTION
The 21064-AA chip implements the full 64-bit Alpha architecture using
Digital's state-of-the-art CMOS-4 technology. In addition to being the CPU
engine designed to power the initial Alpha system products, it will provide
all the longer-term benefits of the new architecture.
By taking advantage of the inherent efficiency of the architecture and by
using high-performance CMOS circuit design techniques, the chip operates at
a clock rate higher than those of any other commercial CMOS microprocessor
in the industry. In addition, the micro-architecture is designed to allow
two instructions to be issued in each clock cycle.
With a total transistor count of 1.68 million devices, the 21064-AA chip is
a complete CPU, including full integer and floating-point execution units.
These units, together with related addressing and branching units, are fully
pipelined, and each is capable of launching a new operation every cycle.
In addition, the chip includes two high-speed primary caches. An 8 Kbyte
instruction cache provides two full 32-bit instructions per clock cycle to
the instruction dispatch unit, and an 8 Kbyte data cache can provide 64-bit
data access during each cycle. The resulting cache bandwidth of 3.2
Gbytes per second far exceeds what could be accomplished if these cache
units were not fully integrated.
The interface from the chip to external elements has been engineered for
high performance and flexibility. This has allowed Digital to incorporate it
into a variety of hardware platforms spanning a broad range of computer
applications. In addition to custom interface solutions, the chip interfaces
to external components via standard off-the-shelf devices.
AVAILABILITY
The 21064-AA microprocessor is available now for your evaluation. Production
quantities will be available in July 1992.
Please contact your local Digital sales office for more information.
VMS FOR ALPHA
HIGHLIGHTS
o Alpha brings the power of RISC computing to the VMS software environment
o The VMS software for Alpha port (based on V5.4-2) preserves and enhances
all VMS operating system strengths
o Moving most VMS applications to the Alpha platform is as easy as
recompile and run
ENHANCING YOUR VMS PROTECTION
Alpha technology enriches the VMS software environment with the performance
leadership of RISC. Thus it enhances the capabilities of the current VMS
environment and provides it with a smooth evolution to the future
information environment.
The VMS operating system will continue to introduce functionality on both
VAX and Alpha systems to meet the increasing requirements of tomorrow's
computing environment. Digital's continued investment in VMS operating
system features and capabilities will maintain VMS benefits for users in the
business critical environment.
PORT OF VMS
VMS software for Alpha is a true "port" of the VMS V5.4-2 sources to the
Alpha architecture, just as other operating systems in the computer industry
are ported. Cross-development tools were built that accepted VAX MACRO32,
BLISS, and C sources and output VMS software for Alpha object
modules/images.
The VMS operating system has not been rewritten or redesigned.
To understand what occurred during the port of the VMS software, consider
the following diagram:
+----------------------------------------------+
Application Layer | Applications |
+-------------+-----------+------------------+ |
User Interface Layer | Motif | DCL | Utilities | |
+-------------+-----------+----------------+ | |
Callable Libraries | Runtime Libraries (RTLs) | | |
+----------------------------------------+ | | |
Higher Operating | System Services | | | |
System Layers | | | | |
+--------------------------------------+ | | | |
| Scheduler, | | | | |
Operating System +--------------+ Swapper, ... | | | | |
Kernel | Memory | | | | | |
| Management | | | | | |
| | | | | | |
| +-------+---------------+ | | | | |
| | Drivers | | | | | |
+------+----+-----------+------+----+--+-+-+-+-+
Hardware | Memory | Disks | Tapes | CPU |
+-----------+-----------+-----------+----------+
Diagram 1: What Software Has Knowledge of Hardware?
The lowest level of the operating system code -- such as boot code, memory
management code, and scheduling code -- was modified to work on Alpha
systems. This "kernel" of an operating system has intimate knowledge of the
hardware. The next layer of operating system software, such as system
services and file services, has very little knowledge about hardware. (For
example, logical name translation or mailbox devices are software constructs
with no hardware-specific knowledge at all.)
Layered above the operating system are the callable runtime libraries
(RTLs) and user interfaces, such as Motif, XUI, and DCL. These software
layers interface with the lower layers of software, not with hardware. All
the various VMS utilities speak to these software layers below them.
Thus, porting the VMS operating system to the Alpha technology means that
all the various software layers that make up the VMS software environment
have been moved to the Alpha system.
MOVING VMS APPLICATIONS
So what does this mean for VMS applications? It means that all the various
pieces of software that make up the VMS operating system will still be
there, still use the same interfaces, and look the same as they did to VAX
VMS programs. All the various runtime libraries, system services, file
systems, application interfaces, network interfaces, layered products, etc.,
will be there for a VMS application to use.
While it is possible for an application to have hardware-specific knowledge
built into it (such as memory page size), it is much more likely to be
protected from hardware specifics by the underlying software layers. Moving
a VMS application to the Alpha environment is easy -- just recompile and
run. Experience in moving user applications to Alpha has proved this to be
true; even the migration of the complex VMS operating system code has gone
smoothly and ahead of schedule.
So when Digital says "VMS is VMS," what Digital is really saying is that all
the layers of software that comprise the VMS environment will be there on
Alpha systems running VMS software just as they are on VAX VMS systems.
System managers, users, programmers -- all will see the same VMS environment
whether it is on a VAX system or on an Alpha system. So Alpha systems
running VMS software provide future protection for the investments you make
today in VAX VMS solutions applications, data, training, support, site
policies and procedures, etc.
64-BIT HARDWARE
64-bit hardware functionality consists of two main features, 64-bit integers
and 64-bit virtual addressing. Alpha systems running VMS software will
initially support 64-bit integers and phase in 64-bit addressing in a later
release.
Alpha systems running VMS software will provide access to 64-bit integers
through standard mechanisms for the various languages such as C and FORTRAN.
Another nice new feature is that 64-bit integers provide an efficient
internal representation of 18 digits of packed decimal data. The COBOL
compiler for Alpha systems will transparently convert packed decimal data
upon input/output to/from this new representation. Packed decimal
calculations will then be done quickly with the new format. This means that
COBOL applications will have good performance on Alpha systems.
What about 64-bit virtual addressing? The VMS operating system has a number
of interfaces, such as item lists, that have 32-bit virtual addresses
embedded in them. Initially, Alpha systems running VMS software will be
implemented with 32-bit virtual addressing to preserve the application
interfaces and ensure easy migration of applications to Alpha. Just as VMS
systems have evolved in the past, from isolated systems to networks to
VAXcluster systems, so the VMS environment will continue to evolve, making
64-bit virtual addressing available to future applications. Digital is
committed to providing a 32-bit environment for applications that have no
need for 64-bit virtual addressing, so these 32-bit applications will not
need changes in the future when Alpha systems running VMS software provide
64-bit virtual addressing capabilities for those applications which do need
a larger address space.
In summary, VMS software for Alpha has been designed so users will quickly
see the same rich-featured, robust environment as VAX VMS users see today:
o Same software development environment
o Same user interface
o Same file system
o Same system management
o Same networking and network management
o Same cluster systems
o Same ...
Please contact your local Digital sales office for more information.
__________
Motif is a registered trademark of the Open Software Foundation, Inc.
DEC OSF/1 FOR ALPHA
HIGHLIGHTS
o DEC OSF/1 for Alpha development is underway, demonstrating Digital's
ability to deliver the industry's leadership UNIX platform
o DEC OSF/1 for Alpha software will offer UNIX users 64-bit,
high-performance systems
o DEC OSF/1 for Alpha software will protect your investments
DEC OSF/1 FOR ALPHA PROGRAM
In May 1988, Digital was instrumental in the formation of the Open Software
Foundation. A year later, Digital announced it would deliver the OSF
operating system technology, OSF/1, as its strategic UNIX platform.
In March 1991, Digital was the first major vendor to offer an OSF/1 Advanced
Development Kit. Last month, Digital was the first major vendor to offer a
commercial implementation of OSF/1, with the announcement of DEC OSF/1 for
MIPS systems (refer to the January 31, 1992, issue of Digital's Customer
Update for a complete description of DEC OSF/1 for MIPS software).
Now, with the Alpha technology announcement featured in this issue, Digital
is poised to deliver the industry's technology and performance leadership
UNIX platform.
Alpha technology will provide performance leadership with 64-bit addressing
to give you more power than ever before. Together, Alpha systems and DEC
OSF/1 software will provide you with leadership hardware plus Digital's
feature-rich implementation of OSF/1. DEC OSF/1 for Alpha software will
include fully integrated OSF/Motif, X11, Logical Volume Manager, realtime
extensions, shared libraries, and DECthreads -- the same features that are
available with DEC OSF/1 for MIPS software. In addition, DEC OSF/1 for Alpha
software will serve to offer Digital's diverse UNIX users, including ULTRIX
and System V users, a single base on which to build the solutions they need.
Digital's approach to UNIX is simple: Provide a single implementation of
OSF/1 that supports multiple architectures, including both MIPS and, with
this technology announcement, Alpha systems. Most DEC OSF/1 applications
written for MIPS can be ported to Alpha by a simple recompile and relink to
take advantage of 64-bit technology. Existing ULTRIX applications can also
be easily ported to Alpha because of the high level of ULTRIX compatibility
in DEC OSF/1 software.
Simply stated, Alpha extends the range of UNIX platforms available to
Digital users. You can buy MIPS systems with ULTRIX or DEC OSF/1 software
today with the assurance that your applications will move easily to
Digital's high-performance Alpha systems. Your application investment is
protected.
Please contact your local Digital sales office for more information.
__________
UNIX is a registered trademark of UNIX System Laboratories, Inc.
OSF/Motif, OSF/1, and OSF are registered trademarks of the Open Software
Foundation, Inc.
System V is a trademark of American Telephone & Telegraph Co.
ALPHA TECHNOLOGY LICENSING
HIGHLIGHTS
o Digital is licensing Alpha technology
o New business practices -- Digital is opening the Alpha technology at all
levels of integration
WHAT WILL DIGITAL LICENSE AND SELL?
Digital's position is simple: to make Alpha technology pervasive and the
leading 64-bit architecture. Discussions have already begun with a number of
companies to enter into a variety of technology alliances and partnerships.
Specificallly, Digital will:
o License the Alpha architecture
o Sell Alpha chips and boards
o License operating systems and environments
o Sell a full range of Alpha-based systems and software
WHAT DOES TECHNOLOGY LICENSING DO FOR YOU?
Alpha licensing broadens your base of choices in operating environment and
applications and offers you the broadest possible range of system families
from embedded products to supercomputers.
Alpha licensing will attract a variety of sources for applications and
specialty systems. Thus you will find compatible systems and products from
other vendors to amplify your application investments.
Digital's licensing plans demonstrate its commitment to open business
practices and open technology.
Please contact your local Digital sales office for more information.
ALPHA IN EMBEDDED APPLICATIONS
HIGHLIGHTS
o Alpha products will be available in chips, boards, boxes, and systems
EMBEDDED APPLICATIONS
Alpha technology is now available to help you integrate computers into your
products. Digital will provide Alpha computers at all levels of integration
-- microprocessors, single-board computers, boxes, and systems.
Digital is selling Alpha chips directly to users. Digital is also working
with several of the leaders in the industry to provide single-board
computers based on Alpha. Through these relationships, Digital will sell
Alpha single-board computers based on popular industry buses such as the
VME, Futurebus+, and TURBOchannel buses. These relationships will provide a
number of alternatives for you in designing Alpha into your products.
Please contact your local Digital sales office for more information.
DIGITAL SERVICES PROGRAMS FOR ALPHA
HIGHLIGHTS
o Digital Services will support Alpha with two major categories of service:
End User Services for new and existing Digital users; and Vendor Services
for other vendors who use the Alpha technology in their products
o End User Services will focus on Consulting Services, Migration Services,
and Educational and Training Services
o Application Migration Centers will help with the planning and orderly
transition from current environments to the new Alpha-based environment
As technology advancement accelerates, services are fast becoming a major
factor in selecting a vendor. In addition to the traditional Digital
Services portfolio, Digital Services will deliver services designed
specifically to meet the needs of Alpha users.
ALPHA END USER SERVICES
End User Services are focused on three main areas: Consulting Services,
Migration Services, and Educational and Training Services. These services
are designed to assist end users in the successful planning, design,
implementation, and management of a new Alpha environment.
Beginning with Alpha, Digital will implement the Advanced Services
Architecture. This program will allow you to interact with services online
through service windows on your screen, which will make it quick and easy to
request service support, order documentation, gain access to informational
databases, and receive updates and corrective code, among other things.
Consulting Services
Consulting Services will be offered to all levels of management. Prudent
business practices call for transitioning to Alpha-based systems in a
planned and orderly fashion. Consulting Services will assist managers in
understanding the impact and benefits of the Alpha technology on their
business -- how the technology can be used for business purposes and for
opening new areas of business opportunities.
Digital Services will help develop strategies for integration or migration
to the Alpha technology, based on the business needs of the company. A
well-planned migration strategy would start now and evolve over a period of
years.
In addition to the Alpha systems migration, the impact on personnel,
operational procedures, and facilities will be addressed.
Migration Services
Migration Services will be available to support Alpha integration and
migration, from application porting to conversion to migration. Code
conversions and porting could be done immediately, while other activities
would occur in a phased manner.
Migration Services are part of Digital's investment protection program, as
they will help you make a smooth transition from your existing environment
to the Alpha technology without losing the benefit of the systems you have
already purchased. There will be three types of support available: you
handle the migration; you work together with Digital; or Digital handles the
entire migration for you.
To support the migration program, Digital is staffing Application Migration
Centers. These resource centers will offer support for planning, application
migration, and integration of Alpha systems. You can obtain help through the
Application Migration Center before and after you purchase Alpha products,
from benchmarking to consulting.
Educational and Training Services
There will be a wide array of educational services available to support
Alpha. Courses will cover the Alpha architecture, hardware implementation,
system and application design implications, and the migration of existing
applications to the new architecture. Digital will also work with you to
develop educational training plans that you can implement to support your
own end users.
Training and courses will also be offered on the OSF and open VMS operating
systems for Alpha systems.
BENEFITS
Working with Digital Services you can:
o Efficiently plan, design, implement, and manage the integration of the
Alpha technology into your existing computing environments.
o Understand the technology benefits of Alpha and how it can be applied to
expand and improve the business processes of your company and reduce time
to market for your products.
o Be assured that your current computing investments will be fully
protected.
ALPHA VENDOR SERVICES
Alpha Vendor Services will be offered to vendors who buy Alpha chips and
incorporate them into their own products. This will include components of
computer or noncomputer products.
Many of these services are an extension of Digital's Multi-Vendor Support
program. Building on established knowledge bases and infrastructures,
Digital will provide "brand name" services on behalf of third-party vendors
that have the Alpha chip imbedded in their products. Thus, Digital can
become the service provider for the vendor. This could include, for example,
utilizing Digital's global logistics and software update systems and
implementation of 800 number call handling.
Watch for further service information for Alpha in future issues of
Digital's Customer Update.
Please contact your local Digital sales office for more information.
__________
OSF is a registered trademark of the Open Software Foundation, Inc.
ALPHA ARCHITECTURE TECHNICAL SUMMARY
HIGHLIGHTS
o Technical details on the exciting Alpha 64-bit RISC architecture and its
25-year, designed-in capabilities
WHAT IS ALPHA?
Alpha is a 64-bit RISC architecture, designed with particular emphasis on
speed, multiple instruction issue, multiple processors, software migration
from VAX VMS and MIPS ULTRIX systems, and long lifetime. The architects
rejected any feature that did not appear to be usable for at least 25 years.
The first chip implementation runs at up to 200 MHz. The speed of Alpha
implementations is expected to scale up from this by at least a factor of
1000 over the next 25 years.
FORMATS
Data Formats
Alpha is a load/store RISC architecture with all operations done between
registers. Alpha has 32 integer registers and 32 floating registers, each 64
bits. Integer register R31 and floating register F31 are always zero.
Longword (32-bit) and quadword (64-bit) integers are supported. Four
floating datatypes are supported: VAX F-float, VAX G-float, IEEE single
(32-bit), and IEEE double (64-bit). Memory is accessed via 64-bit virtual
little-endian byte addresses.
Instruction Formats
Alpha instructions are all 32 bits, in four different instruction formats
specifying 0, 1, 2, or 3 register fields. All formats have a 6-bit opcode.
+-----+-------------------------+
| OP | number | PALcall
+-----+----+--------------------+
| OP | RA | disp | Branch
+-----+----+----+---------------+
| OP | RA | RB | disp | Memory
+-----+----+----+----------+----+
| OP | RA | RB | func. | RC | Operate
+-----+----+----+----------+----+
PALcall instructions specify one of a few dozen complex operations to be
performed. Conditional branches test register RA and specify a signed 21-bit
PC-relative longword target displacement. Subroutine calls put the return
address in RA.
Loads and stores move longwords or quadwords between RA and memory, using RB
plus a signed 16-bit displacement as the memory address.
Operates use source registers RA and RB, writing result register RC. There
is an extended opcode in the 11-bit function field. Integer operates can use
the RB field and part of the function field to specify an 8-bit,
zero-extended literal.
INSTRUCTIONS
PALcall Instructions
The Privileged Architecture Library (PALcall) instructions specify one of a
few dozen complex functions to be performed. These functions deal with
interrupts and exceptions, task switching, virtual memory, and other complex
operations that must be done atomically. PALcall instructions branch to a
privileged library of software subroutines (using the same Alpha instruction
set) that implement an operating system specific set of these complex
operations.
Branch Instructions
Conditional branch instructions can test a register for positive/negative or
for zero/nonzero. They can also test integer registers for even/odd.
Unconditional branch instructions can write a return address into a
register. There is also a calculated jump instruction that branches to an
arbitrary 64-bit address in a register.
Load/Store Instructions
Load and store instructions can move either 32- or 64-bit aligned
quantities. The VAX floating-point load/store instructions swap words to
give a consistent register format for floats. Memory addresses are flat
64-bit virtual addresses with no segmentation. A 32-bit integer datum is
placed in a register in a canonical form that makes 33 copies of the high
bit of the datum. A 32-bit floating datum is placed in a register in a
canonical form that extends the exponent by 3 bits and extends the fraction
with 29 low-order zeros. 32-bit operates preserve these canonical forms.
There are no 8- or 16-bit load/store instructions, but there are facilities
for doing byte manipulation in registers.
Alpha has no 32/64 mode bit or other such device. Compilers, as directed by
user declarations, can generate any mixture of 32- and 64-bit operations.
Integer Operate Instructions
The integer operate instructions manipulate full 64-bit values and include
the usual assortment of arithmetic, compare, logical, and shift
instructions. There are just three 32-bit integer operates: add, subtract,
and multiply. These differ from their 64-bit counterparts only in overflow
detection and in producing 32-bit canonical results.
There is no integer divide instruction.
In addition to the operations found in conventional RISC architectures,
there are scaled add/subtract for quick subscript calculation, 128-bit
multiply for division by a constant and multiprecision arithmetic,
conditional moves for avoiding branches, and an extensive set of in-register
byte manipulation instructions for avoiding single-byte writes.
Rather than keeping a global state bit for integer overflow trap enable, the
enable is encoded in the function field of each instruction. Thus, both
ADDQ/V and ADDQ opcodes exist for specifying 64-bit add with and without
overflow checking. This makes pipelined implementations easier.
Floating-point Operate Instructions
The floating operate instructions include four complete sets of VAX and IEEE
arithmetic, plus conversions between float and integer.
There is no floating square root instruction.
In addition to the operations found in conventional RISC architectures,
there are conditional moves for avoiding branches, and merge sign/exponent
instructions for simple field manipulation.
Rather than keeping global state bits for arithmetic trap enables and
rounding mode, these enable and mode bits are encoded in the function field
of each instruction.
SIGNIFICANT DIFFERENCES FROM CONVENTIONAL RISC PROCESSORS
First, Alpha is a true 64-bit architecture with a minimal number of 32-bit
instructions. It is not a 32-bit architecture that was later expanded to 64
bits.
Second, Alpha was designed to allow very-high-speed implementations. The
instructions are very simple (no load-four-registers-unaligned-and-check-
for-bytes-of-zero). There are no special registers that would prevent
pipelining multiple instances of the same operations (no MQ register and no
condition codes). The instructions interact with each other only by one
instruction writing a register or memory, and another one reading from the
same place. This makes it particularly easy to build implementations that
issue multiple instructions every CPU cycle. (The first implementation, in
fact, issues two instructions every cycle.) There are no implementation-
specific pipeline timing hazards, no load-delay slots, and no branch-delay
slots. These features would make it difficult to maintain binary
compatibility across multiple implementations and difficult to maintain full
speed on multiple-issue implementations.
Alpha is unconventional in the approach to byte manipulation. Single-byte
stores found in conventional RISC architectures force cache and memory
implementations to include byte shift-and-mask logic, and sequencer logic to
perform read-modify-write on memory words. This approach is awkward to
implement quickly and tends to slow down cache access to normal 32- or
64-bit aligned quantities. It also makes it awkward to build a high-speed
error-correcting, write-back cache, which is often needed to keep a very
fast RISC implementation busy. It also can make it difficult to pipeline
multiple byte operations.
Instead, the byte .hifting and masking is done in Alpha with normal 64-bit
register-to-register instructions, crafted to keep the sequences short.
Alpha is also unconventional in the approach to arithmetic traps. In
contrast to conventional RISC architectures, Alpha arithmetic traps
(overflow, underflow, etc.) are imprecise -- they can be delivered an
arbitrary number of instructions after the instruction that triggered the
trap, and traps from many different instructions can be reported at once.
This makes implementations that use pipelining and multiple issue
substantially easier to build.
If precise arithmetic exceptions are desired, trap barrier instructions can
be explicitly inserted in the program to force traps to be delivered at
specific points.
Alpha is also unconventional in the approach to multiprocessor shared
memory. As viewed from a second processor (including an I/O device), a
sequence of reads and writes issued by one processor may be arbitrarily
reordered by an implementation. This allows implementations to use
multibank caches, bypassed write buffers, write merging, pipelined writes
with retry on error, etc. If strict ordering between two accesses must be
maintained, memory barrier instructions can be explicitly inserted in the
program.
The basic multiprocessor interlocking primitive is a RISC-style load_locked,
modify, store_conditional sequence. If the sequence runs without interrupt,
exception, or an interfering write from another processor, then the
conditional store succeeds. Otherwise, the store fails and the program
eventually must branch back and retry the sequence. This style of
interlocking scales well with very fast caches and makes Alpha an especially
attractive architecture for building multiple-processor systems.
Alpha includes a number of hints for implementations, all aimed at allowing
higher speed. Calculated jumps have a target hint that can allow much faster
subroutine calls and returns. There are prefetching hints for the memory
system that can allow much higher cache hit rates. There are also
granularity hints for the virtual-address mapping that can allow much more
effective use of translation lookaside buffers for big contiguous
structures.
Alpha includes a very flexible privileged library of software for operating
system specific operations, invoked with PALcall instructions. This library
allows Alpha to run full VMS functionality using one version of this
software library that mirrors many of the VAX system features, and to run
OSF/1 software using a different version that mirrors many of the MIPS
system features. Other versions could be tailored for realtime, teaching,
etc. The PALcall instructions allow Alpha to run the VMS operating system
with little more hardware than a conventional RISC machine has (the PAL mode
bit itself, plus 4 extra protection bits in each TB entry). This library
makes Alpha an especially attractive architecture for multiple operating
systems.
Finally, Alpha is not strongly biased toward only one or two programming
languages. It is an attractive architecture for compiling at least a dozen
different languages.
Please contact your local Digital sales office for more information.
