ACS-1
Encyclopedia
The ACS-1 and ACS-360 are two related supercomputers designed by IBM
as part of the IBM Advanced Computing Systems project from 1961 to 1969. Although the designs were never finished and no models ever went into production, the project spawned a number of organizational techniques and architectural innovations that have since become incorporated into nearly all high-performance computers
in existence today. Many of the ideas resulting from the project directly influenced the development of the IBM RS/6000
and, more recently, have contributed to the Explicitly Parallel Instruction Computing
(EPIC) computing paradigm used by Intel
and HP
in high-performance processors.
. A number of significant computer pioneers contributed to the project, including John Cocke
, Herb Schorr, Frances Allen
, Gene Amdahl
, and Lynn Conway
.
A May 1968 decision by IBM to modify the project to support S/360 compatibility resulted in the name change from ACS-1 to ACS-360 for the computer being designed. At its peak, the ACS-360 project involved over 200 engineers and staff.
The ACS-360 project was canceled in May 1969; however many of the innovations resulting from the project would eventually find direct realization in the IBM RS/6000
series of machines (now the IBM System p
line of workstations and servers), apart from influencing the design of other machines and architectures.
CPU design techniques that would become fundamental to the design of modern computer architectures and systems:
IBM
International Business Machines Corporation or IBM is an American multinational technology and consulting corporation headquartered in Armonk, New York, United States. IBM manufactures and sells computer hardware and software, and it offers infrastructure, hosting and consulting services in areas...
as part of the IBM Advanced Computing Systems project from 1961 to 1969. Although the designs were never finished and no models ever went into production, the project spawned a number of organizational techniques and architectural innovations that have since become incorporated into nearly all high-performance computers
High-performance computing
High-performance computing uses supercomputers and computer clusters to solve advanced computation problems. Today, computer systems approaching the teraflops-region are counted as HPC-computers.-Overview:...
in existence today. Many of the ideas resulting from the project directly influenced the development of the IBM RS/6000
IBM System p
The System p, formerly known as RS/6000, was IBM's RISC/UNIX-based server and workstation product line.In April 2008, IBM announced a rebranding of the System p and its unification with the System i platform. The resulting product line is called IBM Power Systems.-History:It was originally a line...
and, more recently, have contributed to the Explicitly Parallel Instruction Computing
Explicitly Parallel Instruction Computing
Explicitly parallel instruction computing is a term coined in 1997 by the HP–Intel alliance to describe a computing paradigm that researchers had been investigating since the early 1980s. This paradigm is also called Independence architectures...
(EPIC) computing paradigm used by Intel
Intel Corporation
Intel Corporation is an American multinational semiconductor chip maker corporation headquartered in Santa Clara, California, United States and the world's largest semiconductor chip maker, based on revenue. It is the inventor of the x86 series of microprocessors, the processors found in most...
and HP
Hewlett-Packard
Hewlett-Packard Company or HP is an American multinational information technology corporation headquartered in Palo Alto, California, USA that provides products, technologies, softwares, solutions and services to consumers, small- and medium-sized businesses and large enterprises, including...
in high-performance processors.
History
The ACS project began in 1961 as Project Y with a goal of “building a machine that was one hundred times faster than Stretch.” Initial work began at the IBM Watson Research CenterThomas J. Watson Research Center
The Thomas J. Watson Research Center is the headquarters for the IBM Research Division.The center is on three sites, with the main laboratory in Yorktown Heights, New York, 38 miles north of New York City, a building in Hawthorne, New York, and offices in Cambridge, Massachusetts.- Overview :The...
. A number of significant computer pioneers contributed to the project, including John Cocke
John Cocke
John Cocke was an American computer scientist recognized for his large contribution to computer architecture and optimizing compiler design. He is considered by many to be "the father of RISC architecture."...
, Herb Schorr, Frances Allen
Frances E. Allen
Frances Elizabeth "Fran" Allen is an American computer scientist and pioneer in the field of optimizing compilers. Her achievements include seminal work in compilers, code optimization, and parallelization...
, Gene Amdahl
Gene Amdahl
Gene Myron Amdahl is a Norwegian-American computer architect and high-tech entrepreneur, chiefly known for his work on mainframe computers at IBM and later his own companies, especially Amdahl Corporation...
, and Lynn Conway
Lynn Conway
Lynn Conway is an American computer scientist, electrical engineer, inventor, trans woman, and activist for the transgender community....
.
A May 1968 decision by IBM to modify the project to support S/360 compatibility resulted in the name change from ACS-1 to ACS-360 for the computer being designed. At its peak, the ACS-360 project involved over 200 engineers and staff.
The ACS-360 project was canceled in May 1969; however many of the innovations resulting from the project would eventually find direct realization in the IBM RS/6000
IBM System p
The System p, formerly known as RS/6000, was IBM's RISC/UNIX-based server and workstation product line.In April 2008, IBM announced a rebranding of the System p and its unification with the System i platform. The resulting product line is called IBM Power Systems.-History:It was originally a line...
series of machines (now the IBM System p
IBM System p
The System p, formerly known as RS/6000, was IBM's RISC/UNIX-based server and workstation product line.In April 2008, IBM announced a rebranding of the System p and its unification with the System i platform. The resulting product line is called IBM Power Systems.-History:It was originally a line...
line of workstations and servers), apart from influencing the design of other machines and architectures.
Influence
Although neither the ACS-1 nor the ACS-360 was ever manufactured, the IBM Advanced Computing Systems group responsible for their design developed architectural innovations and pioneered a number of RISCReduced instruction set computer
Reduced instruction set computing, or RISC , is a CPU design strategy based on the insight that simplified instructions can provide higher performance if this simplicity enables much faster execution of each instruction. A computer based on this strategy is a reduced instruction set computer...
CPU design techniques that would become fundamental to the design of modern computer architectures and systems:
- Aggressive reduction in the number of logic gate levels for pipeline stages to reduce the cycle time
- Tight integration between processor and memory
- Cache memory with streamlined I/O to/from cache
- Compiler optimization techniques
- Virtual-memory operating systems
- Multiple instruction decode and issue (a first)
- Use of a branch target buffer (a first)
- Multithreading implemented in hardware (a first for IBM)
- Dynamic instruction scheduling/out-of-order executionOut-of-order executionIn computer engineering, out-of-order execution is a paradigm used in most high-performance microprocessors to make use of instruction cycles that would otherwise be wasted by a certain type of costly delay...
- Hardware register renamingRegister renamingIn computer architecture, register renaming refers to a technique used to avoid unnecessary serialization of program operations imposed by the reuse of registers by those operations.-Problem definition:...
- Instruction predication
- Branch prediction
- Level-sensitive scan design (used by IBM)
- Fixed-head hard disks
- Air-cooled high-speed LSI circuits
- Advanced simulation tools used in the design process
External links
- IBM Advanced Computing Systems (ACS) — 1961–1969 — Documentation project for the IBM ACS-1 supercomputer maintained by Mark Smotherman