IBM System/390 ES/9000 Enterprise Systems Architecture ESA family

IBM System/390 ES/9000

Manufacturer	International Business Machines Corporation (IBM)
Product family	18 initial models, followed by others
Release date	September 5, 1990 (1990-09-05)
Discontinued	May 24, 1998 for the first 18 initial models
Operating system	VSE/ESA, VM/ESA and MVS/ESA
Memory	up to 9 Gigabytes
Predecessor	IBM 3090
Successor	IBM_System_z
Website	Official website IBM Archives "System/390 Announcement". IBM Archives. IBM. Retrieved 2017-01-29.

"System/390 introduces the IBM Enterprise System/9000 family"
was how IBM Marketing simultaneously announced on September 5, 1990 its next mainframe offerings, using two important numbered names:

• 390,^[1] as in 360, 370, ... and
• 9000,^[2][3] as in 90, as in 1960 for 360, 1970 for 370, ...

The introduction covered new architecture, new hardware and new software.

Although the 9000 family name was mentioned first in some of the day's announcements, it was clear by "the end of the day" that it was "for System/390,"^[2] although it was the name S/390 that was placed on some of the actual "boxes" later shipped.^{[4][NB 1]}

The newly introduced ESA/390 architecture brought with it

• MVS/ESA
• VM/ESA and
• VSE/ESA

These systems followed the IBM 3090, with over a decade of follow-ons, eventually leading to the IBM System z.

Models

New models were offered on an ongoing basis.^[5]

Initial ES/9000 models

18^[3] models^{[NB 2]} were announced September 5, 1990 for the ES/9000, the successor of the IBM 3090.

ES/9000 features

• ESCON fiber optic channels
• Two of the models could be configured with as much as 9 Gigabytes of main memory.
• Optional vector facilities were available on 14 of the 18 models
• The number of vector processors coould be 1, 2, 3, 4 or 6.
• Six models were air-cooled models (and eight water-cooled models); 4 are rack-mounted.

Cooling

Water-cooled ES/9000 models included ES/9021-900,^[6] -820, -720, -620, -580, -500, -340 and -330.
Air-cooled ES/9000 models ^[7] included standalone ES/9121-480, -440, -320, -260, -210, -190, and rack mounted: ES/9221-421, -211, -170, -150, -130, -120.

Competitive Cooling

By the late 1970s and early 1980s, patented technology allowed Amdahl mainframes of this era to be completely air-cooled, unlike IBM systems that required chilled water and its supporting infrastructure.^[8]The 8 largest of the 18 models of the ES/9000 systems introduced in 1990 were water-cooled; the other ten were air-cooled.^[2]

LPAR

Logical Partitions, LPARs, a standard function on ES/9000 processors, are a feature whereby IBM's Processor Resource/Systems Manager (PR/SM), allows different operating systems to run concurrently in separate logical partitions (LPARs), with a high degree of isolation.

This was introduced as part of IBM's moving towards "lights-out" operation and increased control of multiple system configurations.

ESA/390 architecture

ESA/390 (Enterprise Systems Architecture/390) was introduced in September 1990^[9][10] and was IBM's last 31-bit-address/32-bit-data mainframe computing design, copied by Amdahl, Hitachi, and Fujitsu among other competitors. It was the successor of Enterprise Systems Architecture/370 (ESA/370) and, in turn, was succeeded by the 64-bit z/Architecture in 2000.

Machines supporting the architecture have been sold under the brand System/390 (S/390) from the beginning of the 1990s. The 9672 implementations of System/390 were the first high-end IBM mainframe architecture implemented first with CMOS CPU electronics rather than the traditional bipolar logic.

Architecture and memory

Front cover of the IBM S/390 Parallel Enterprise Server Generation 5

The architecture employs a channel I/O subsystem in the System/360 tradition, offloading almost all I/O activity to specialized hardware. It also includes a standard set^[10] of CCW opcodes that new equipment is expected to provide.

The architecture maintains problem state backward compatibility with the 24-bit-address/32-bit-data System/360 (1964) and all intermediate large system 24/31-bit-address/32-bit-data architectures (System/370, System/370-XA, and ESA/370). However, the I/O subsystem is based on System/370 Extended Architecture (S/370-XA), not on the original S/370 I/O instructions.

ESA/390 is arguably a 32-bit architecture; as with System/360, System/370, 370-XA, and ESA/370, the general-purpose registers are 32 bits long, and the arithmetic instructions support 32-bit arithmetic. Only byte-addressable real memory (Central Storage) and Virtual Storage addressing is limited to 31 bits. (IBM reserved the most significant bit to easily support applications expecting 24-bit addressing, as well as to sidestep a problem with extending two instructions to handle 32-bit unsigned addresses.)

In fact, total system memory is not limited to 31 bits (2 GB).^{[NB 3]} While the virtual storage of a single address space cannot exceed 2 GB, ESA/390 supports multiple concurrent 2GB address spaces. Further, each address space can have Dataspaces associated with it, each of which can have up to 2 GB of Virtual Storage. While Central Storage is limited to 2GB additional memory can be configured as expanded storage. With Expanded Storage 4KB pages can be moved between Central Storage and Expanded Storage. Expanded Storage can be used for a number of things such as ultra-fast paging, for disk caching and virtual disks within the VM/CMS operating system. Under Linux/390 this memory cannot be used for disk caching; instead, it is supported by a block device driver, allowing to use it as ultra-fast swap space and for RAM drives.

In addition, a machine may be divided into Logical Partitions (LPARs), each with its own system memory so that multiple operating systems may run concurrently on one machine.

An important capability to form a Parallel Sysplex was added to the architecture in 1994.

Some PC-based IBM-compatible mainframes which provide ESA/390 processors in smaller machines have been released over time, but are only intended for software development.

The Hercules emulator is a portable ESA/390 and z/Architecture machine emulator which supports enough devices to boot many ESA/390 operating systems. Since it is written in pure C, it has been ported to many platforms, including S/390 itself. A commercial emulation product for IBM xSeries with higher execution speed is also available.

Common I/O Device Commands

2.0 Chapter 2. Specific I/O-Device Commands in Enterprise Systems Architecture/390 Common I/O-Device Commands^[10] shows the following commands.

S/390 computers

The ESA/370 architecture was introduced with the IBM 3090 mainframe and the ESA/390 architecture was introduced with the IBM ES/9000 family of mainframes.

Introduced in 1994, the six generations of the IBM 9672 machines were the first CMOS, microprocessor based systems intended for the high end. The initial generations were slower than the largest ES/9000 sold in parallel, but the fifth and sixth generations were the largest and most powerful ESA/390 machines built.^[11]

In the course of next generations, CPUs added more instructions and increased performance. All 9672s were CMOS, but were slower than the 9021 bipolar machines until the G5 models. CMOS designs permitted much smaller mainframes, such as the Multiprise 3000 introduced in 1999, which was actually based on 9672 G5. The 9672 G3 model and the Multiprise 2000 were the last versions to support pre-XA System/370 mode.

See also

• List of related IBM mainframes
• IBM System/360
• IBM System/370
• IBM 303X
• IBM 308X
• IBM 3090
• IBM System z

Photos

• http://sysrun.haifa.il.ibm.com/ibm/history/exhibits/mainframe/images/2423PH9000.jpg

External links

Wikimedia Commons has media related to IBM S/390.

• Generations of the IBM 360/370/3090/390 by Lars Poulsen with multiple links and references
• Exterior and interior images of the IBM 390 at The Jim Austin Computer Collection, UK Computer Museum. Accessed February 2012
• Porting GCC to the IBM S/390 platform
• IBM Archives: A Brief History of the IBM ES/9000, System/390 AND zSeries

Notes

References