ICL Series 39
Encyclopedia
The ICL Series 39 was a range of mainframe
and minicomputer
computer
systems released by the UK manufacturer ICL in 1985.
line, and was introduced as two ranges:
which allowed nodes to be up to 1000 metres apart.
The Series 39 range introduced Nodal Architecture, a novel implementation of distributed shared memory
that can be seen as a hybrid of a multiprocessor
system and a cluster design. Each machine consists of a number of nodes
, and each node contains its own order-code processor and main memory. Virtual machines are typically located (at any one time) on one node, but have the capability to run on any node and to be relocated from one node to another. Discs and other peripherals are shared between nodes. Nodes are connected using a high-speed optical bus (Macrolan) using multiple fibre optic cables, which is used to provide applications with a virtual shared memory. Memory segments that are marked as shared (public or global segments) are replicated to each node, with updates being broadcast over the inter-node network. Processes which use unshared memory segments (nodal or local) run in complete isolation from other nodes and processes.
The semaphore instructions
prove their worth by controlling access to the shared writable memory segments while allowing the contents to be moved around efficiently.
Overall, a well configured Series 39 with VME had an architecture which can provide a significant degree of proofing against disasters, a nod to the abortive VME/T ideas of the previous decade.
All Series 39 machines were supported by a set of waist height peripheral 'Cabinets' (connected via fibre optic cables via one or more Multi Port Switch Units or MPSU's) providing disk storage capabilities:-
Cabinet 1 was the name given to the DM1 Series 39 Level 30 (and 20/15/25/35 variants) core system.
All Series 39 machines also featured a Node Support Computer (NSC) hosted on their Storage Motherboards - this was x86 architecture and acted much like today's ILO or DRAC cards on HP/Dell Servers and allowed Support Staff to manage the Nodes remotely including the ability to completely stop and restart the main Nodes.
A mid-life upgrade to "S3X" ("Essex") processors and microcodes saw:
and VME nodes on the same system.
Trimetra in turn was replaced by Fujitsu's mainframe platform, Nova, which emulates the Trimetra architecture on generic Unisys
ES7000
Intel-based server hardware.
Nova itself was phased out in 2007 and replaced with SuperNova, which runs OpenVME on top of Windows Server or Linux, using as few as two CPUs on generic Wintel
server hardware.
The transition of the "ICL mainframe" to a pure software product is thus complete, enabling Fujitsu to concentrate on VME support and development without having to keep up with hardware technology.
Mainframe computer
Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...
and minicomputer
Minicomputer
A minicomputer is a class of multi-user computers that lies in the middle range of the computing spectrum, in between the largest multi-user systems and the smallest single-user systems...
computer
Computer
A computer is a programmable machine designed to sequentially and automatically carry out a sequence of arithmetic or logical operations. The particular sequence of operations can be changed readily, allowing the computer to solve more than one kind of problem...
systems released by the UK manufacturer ICL in 1985.
Origins
The Series 39 range was based upon the New Range concept and the VME operating system from the company's ICL 2900ICL 2900 Series
The ICL 2900 Series was a range of mainframe computer systems announced by the UK manufacturer ICL on 9 October 1974. The company had started development, under the name "New Range" immediately on its formation in 1968...
line, and was introduced as two ranges:
- Series 39 "Estriel" systems (Series 39 Level 40 and above, including multinodes), which replaced previous mid-range and large processors from the 2900 range, and needed a full computer room environment
- Series 39 DM1 systems (up to Series 39 Level 30), which were intended to replace the smaller processors such as the ICT1901/2, the ICL2903/4 and the ME29 ranges. These brought mainframe class operating system facilities into the office environment, a first for ICL
Design
The original Series 39 introduced the "S3L" (whose corrupt pronunciation resulted in the name "Estriel") processors and microcodes, and a nodal architecture (see ICL VME) which is a form of Non-Uniform Memory AccessNon-Uniform Memory Access
Non-Uniform Memory Access is a computer memory design used in Multiprocessing, where the memory access time depends on the memory location relative to a processor...
which allowed nodes to be up to 1000 metres apart.
The Series 39 range introduced Nodal Architecture, a novel implementation of distributed shared memory
Distributed shared memory
Distributed Shared Memory , in Computer Architecture is a form of memory architecture where the memories can be addressed as one address space...
that can be seen as a hybrid of a multiprocessor
Multiprocessor
Computer system having two or more processing units each sharing main memory and peripherals, in order to simultaneously process programs.Sometimes the term Multiprocessor is confused with the term Multiprocessing....
system and a cluster design. Each machine consists of a number of nodes
Node (networking)
In communication networks, a node is a connection point, either a redistribution point or a communication endpoint . The definition of a node depends on the network and protocol layer referred to...
, and each node contains its own order-code processor and main memory. Virtual machines are typically located (at any one time) on one node, but have the capability to run on any node and to be relocated from one node to another. Discs and other peripherals are shared between nodes. Nodes are connected using a high-speed optical bus (Macrolan) using multiple fibre optic cables, which is used to provide applications with a virtual shared memory. Memory segments that are marked as shared (public or global segments) are replicated to each node, with updates being broadcast over the inter-node network. Processes which use unshared memory segments (nodal or local) run in complete isolation from other nodes and processes.
The semaphore instructions
Semaphore (programming)
In computer science, a semaphore is a variable or abstract data type that provides a simple but useful abstraction for controlling access by multiple processes to a common resource in a parallel programming environment....
prove their worth by controlling access to the shared writable memory segments while allowing the contents to be moved around efficiently.
Overall, a well configured Series 39 with VME had an architecture which can provide a significant degree of proofing against disasters, a nod to the abortive VME/T ideas of the previous decade.
All Series 39 machines were supported by a set of waist height peripheral 'Cabinets' (connected via fibre optic cables via one or more Multi Port Switch Units or MPSU's) providing disk storage capabilities:-
- Cabinet 2 - these were the main Disk Storage Cabinets holding a pair of 330Mb 8 inch "Swallow" Hard Drives
- Cabinet 3 - these were an expansion cabinet to the Cabinet 2 and could hold up to four more 330Mb 8 inch "Swallow" Hard Drives
- Cabinet 4 - these were a bridge cabinet would was used to connect Series 39 to older 2900 Diskpack based Storage (such as EDS200's)
Cabinet 1 was the name given to the DM1 Series 39 Level 30 (and 20/15/25/35 variants) core system.
All Series 39 machines also featured a Node Support Computer (NSC) hosted on their Storage Motherboards - this was x86 architecture and acted much like today's ILO or DRAC cards on HP/Dell Servers and allowed Support Staff to manage the Nodes remotely including the ability to completely stop and restart the main Nodes.
Evolution
In the mid 1980's the Series 39 Level 30 was supplemented by a Level 20 variant which was a forcibly underclocked Level 30 (using wire links on a daughterboard). In the late 80's these were both replaced by Level 15, 25 and 35 variants which also carried various levels of clocking state but featured more memory than their predecessors and could also be fitted with Dual OCP and IOC motherboards for even more computing and I/O capability.A mid-life upgrade to "S3X" ("Essex") processors and microcodes saw:
- The introduction of SX systems in 1990 to replace the Estriel ("S3L") systems
- The introduction of DX systems in 1993 to replace the DM1 systems
Replacement
The Series 39 SX/DX was replaced by the Trimetra system (initially the SY/DY, and then the DL/SL ranges), which made more use of industry standard hardware and allowed for both WindowsMicrosoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
and VME nodes on the same system.
Trimetra in turn was replaced by Fujitsu's mainframe platform, Nova, which emulates the Trimetra architecture on generic Unisys
Unisys
Unisys Corporation , headquartered in Blue Bell, Pennsylvania, United States, and incorporated in Delaware, is a long established business whose core products now involves computing and networking.-History:...
ES7000
ES7000
The ES7000 is Unisys's x86/Windows, Linux and Solaris-based server product line. The "ES7000" brand has been used since 1999, although variants and models within the family support various processor and bus architectures. The server is marketed and positioned as a scale-up platform where scale-out...
Intel-based server hardware.
Nova itself was phased out in 2007 and replaced with SuperNova, which runs OpenVME on top of Windows Server or Linux, using as few as two CPUs on generic Wintel
Wintel
Wintel is a portmanteau of Windows and Intel, referring to personal computers using Intel x86 compatible processors running Microsoft Windows...
server hardware.
The transition of the "ICL mainframe" to a pure software product is thus complete, enabling Fujitsu to concentrate on VME support and development without having to keep up with hardware technology.