The IBM 9370 systems are "baby mainframe"

midrange computer Midrange computers, or midrange systems, were a class of computer systems that fell in between mainframe computers and microcomputers. This class of machine emerged in the 1960s, with models from Digital Equipment Corporation ( PDP line), Data Ge ...

s, released 1986 at the very low end of, and compatible with

System/370 The IBM System/370 (S/370) is a model range of IBM mainframe computers announced on June 30, 1970, as the successors to the System/360 family. The series mostly maintains backward compatibility with the S/360, allowing an easy migration path ...

. The media of the day, referring to the

VAX VAX (an acronym for Virtual Address eXtension) is a series of computers featuring a 32-bit instruction set architecture (ISA) and virtual memory that was developed and sold by Digital Equipment Corporation (DEC) in the late 20th century. The V ...

systems manufactured by

Digital Equipment Corporation Digital Equipment Corporation (DEC ), using the trademark Digital, was a major American company in the computer industry from the 1960s to the 1990s. The company was co-founded by Ken Olsen and Harlan Anderson in 1957. Olsen was president un ...

(DEC), carried IBM's alleged " VAX Killer" phrase, albeit often skeptically.

History

The IBM 9370 was created in the aftermath of the failed Fort Knox project, which attempted to consolidate all of IBM's midrange systems into a single

IBM 801 The 801 was an experimental central processing unit (CPU) design developed by IBM during the 1970s. It is considered to be the first modern RISC design, relying on processor registers for all computations and eliminating the many variant addressi ...

-based hardware platform. The announcementIBM 9370 INFORMATION SYSTEM OVERVIEW
/ref> described the IBM 9370 as a " super-mini computer" for commercial and engineering/scientific use—compact, rack-mounted, designed for an office environment, not needing a data center to be used. At the time of announcement the systems were positioned between IBM's midrange systems (

IBM System/36 The IBM System/36 (often abbreviated as S/36) was a midrange computer marketed by IBM from 1983 to 2000 - a multi-user, multi-tasking successor to the System/34. Like the System/34 and the older System/32, the System/36 was primarily progr ...

and

IBM System/38 The System/38 is a discontinued minicomputer and midrange computer manufactured and sold by IBM. The system was announced in 1978. The System/38 has 48-bit addressing, which was unique for the time, and a novel integrated database system. It w ...

), and the

IBM 4300 The IBM 4300 series are mid-range systems compatible with System/370 that were sold from 1979 through 1992. They featured modest electrical and cooling requirements, and thus did not require a data center environment. They had a disruptive effect ...

mainframe series in performance. The IBM 9370 was partially a replacement for the also-not-so-successful

IBM 8100 The IBM 8100 Information System, announced Oct. 3, 1978, was at one time IBM’s principal distributed processing engine, providing local processing capability under two incompatible operating systems ( DPPX and DPCX) and was a follow-on to the ...

distributed processing engine. High-level 9370 models were mentioned as a substitution when low-level 4300 models were withdrawn from marketing 1987. Intended to be sold in large amounts as departmental machines ("

killers"), the 9370 initially suffered from lack of software and the failure of IBM to market it properly. Nevertheless, the systems were popular at least with users actually ''needing'' System/370 compatibility while not wanting to accept the expense of a larger system (like e.g. smaller software houses) or with users (like some large IBM customers) preferring hierarchically structured distributed processing solutions rigidly managed by central communication controllers like

IBM 37xx IBM 37xx (or 37x5) is a family of IBM Systems Network Architecture (SNA) programmable communications controllers used mainly in mainframe environments. All members of the family ran one of three IBM-supplied programs. *''Emulation Program'' (E ...

. By 1990 the 9370 line had around 6,300 installed systems and generated over 2 billion dollars in sales for IBM. The relatively lacklustre commercial success of the 9370 served as an impetus for the creation of the much more successful

AS/400 The IBM AS/400 (Application System/400) is a family of midrange computers from IBM announced in June 1988 and released in August 1988. It was the successor to the System/36 and System/38 platforms, and ran the OS/400 operating system. Lower-cos ...

midrange systems. While becoming part of the IBM Enterprise Systems Architecture in 1988 ("ES/9370" like "ES/4300" and "ES/3090"), the 9370s weren't XA systems. In 1990 IBM announced the "

ES/9000 The IBM System/390 is a discontinued mainframe product family implementing the ESA/390, the fifth generation of the System/360 instruction set architecture. The first computers to use the ESA/390 were the Enterprise System/9000 (ES/9000) ...

" series; the rack-mounted models 120-170 with 31-bit ''Enterprise Systems Architecture'' (ESA) and

ESCON ESCON (Enterprise Systems Connection) is a data connection created by IBM, and is commonly used to connect their mainframe computers to peripheral devices such as disk storage, tape drives and IBM 3270 display controllers. ESCON is an opt ...

were the suggested upgrades for ES/9370 users.

Models and options

Early models

The original 9370 hardware was based on technology created for the Fort Knox project - reusing some of the

-based processor design, and the SPD I/O bus which was derived from the

Series/1 The IBM Series/1 is a 16-bit minicomputer, introduced in 1976, that in many respects competed with other minicomputers of the time, such as the PDP-11 from Digital Equipment Corporation and similar offerings from Data General and Hewlett-Packar ...

bus. All models included a floating-point accelerator as well as a processor console to install, operate and maintain the system. A militarized variant of the 9370 named the ''System/MIL-370'' was announced alongside the original 9370 models, designed to operate in harsher environmental conditions than the standard 9370 hardware. Each ''DASD/Tape Controller'' had eight device addresses and provided a data transfer rate of 3 MB. IBM 9332 (368 MB) and IBM 9335 (824 MB) DASD and IBM 9347 nine-track half-inch tape have been announced for the 9370s. Each ''Workstation Controller'' could interface up to 32 IBM 3270 terminals / printers. Software for all models included

VM/SP VM (often: VM/CMS) is a family of IBM virtual machine operating systems used on IBM mainframes System/370, System/390, zSeries, System z and compatible systems, including the Hercules emulator for personal computers. The following version ...

+VM/IS, VSE/SP, and VM/SP+ IX/370, while MVS/SP was only available for larger models.

Enterprise systems architecture models

An upgrade (''Miscellaneous Equipment Specification'', MES) was available which involved - among other things - replacing the 9332 FBA drives with CKD enabled DASDs. In 1988, ''Distributed Processing Programming Executive'' DPPX/370 for ES/9370 was made available to customers wanting to migrateIEEE Xplore - Porting DPPX from the IBM 8100 to the IBM ES/9370
/ref> from the

running DPPX. The "Micro Channel 370" Models 010, 012, 014 (later 110, 112, 114) ES/9371 introduced in 1990 used the

Micro Channel Micro Channel architecture, or the Micro Channel bus, is a proprietary 16- or 32-bit parallel computer bus introduced by IBM in 1987 which was used on PS/2 and other computers until the mid-1990s. Its name is commonly abbreviated as "MCA", al ...

bus and a 386 CPU for input/output (I/O) processing. Additionally, a dual-processor model was offered, providing a second 386 CPU for DOS and OS/2 applications, implementing a high-speed link between the processors. With the models mentioned, APPC support was added, using LU6.2 based on SNA PU2.1.

Notes

References

External links

IBM Archives: 1986
(With photos of IBM 9370)
IBM 9370 product announcement
{{DEFAULTSORT:IBM 9370 9370 32-bit computers