PC-based IBM-compatible mainframes
Encyclopedia
Since the rise of the personal computer
in the 1980s, IBM
and other vendors have created PC-based IBM-compatible mainframes which are compatible with the larger IBM mainframe computer
s. For a period of time PC-based mainframe-compatible systems had a lower price and did not require as much electricity or floor space. However, they sacrificed performance and were not as dependable as mainframe-class hardware. These products have been popular with mainframe developers, in education and training settings, for very small companies with non-critical processing, and in certain disaster relief roles (such as field insurance adjustment systems for hurricane relief).
required by the machines. Modern mainframes are now physically comparatively small and require little or no special building arrangements.
. This product used microcode to execute many of the System/370's processor instructions, so that it could run a slightly modified version of IBM's APL mainframe program interpreter.
operating system. It was a freestanding tower, that connected to a MCA
card installed in a PS/2
Model 60, 70, or 80.
card that can be added to a PS/2
or RS/6000
computer to run System/370 OSs (like MUSIC/SP
, VM
, VSE
) parallel to OS/2
(in PS/2) or AIX
(in RS/6000) supporting multiple concurrent users. It is a complete implementation of the S/370 Processor including a FPU
co-processor and 16 MB memory. Management and standard I/O channels are provided via the host OS/hardware. An additional 370 channel card can be added to provide mainframe-specific I/O such as 3270 local control units, 3400/3480 tape drives or 7171 protocol converters.
processor and 32 to 512 MB of RAM, depending on the configuration. The MCA
P/390 expansion card can be installed in any MCA
RS/6000 system, while the PCI
P/390 card can be installed in a number of early PCI
RS/6000s; all such configurations are referred to as an R/390. R/390 servers need to run AIX version 4 as the host operating system.
expansion slots and removed two MCA slots.
(which has the same size). Only 256 MB of ECC Memory and a single CMOS main processor (performance about 8 MIPS) are used; the S/390 CPU used in the Integrated Server is in fact the P/390 E-card. A Pentium II
is used as IOSP (I/O Service Processor). It supports four ESCON
and to four parallel channels. Standard PCI and ISA slots are present. A maximum of 255 GB internal harddisks are supported (16x 18GB HDs, with 2x HDs for redundancy). The supported OSs are OS/390, MVS/ESA, VM/ESA and VSE/ESA.
mainframe product line. The SQ100 is the slower configuration, running on dual-core Xeon E7220 processors, and is capable of up to 200RPF of performance. The SQ200 was introduced more recently, uses 6-core Xeon X7542 processors, and has performance of up to 700RPF. All x86-based BS2000 mainframes can run Linux or Windows in separate partitions. Fujitsu also continues to make custom S/390-native processors and mainframe hardware for the high end of its BS2000 line.
server or a ThinkPad
laptop.
Another popular emulator is the open source Hercules emulator, which has been in development since 1999 and emulates the System/370, System/390, and z/Architecture instruction sets. While Hercules cannot legally run modern IBM operating systems, earlier System/370 operating systems are in the public domain and can be legally run on Hercules. According to Tom Lehmann, cofounder of TurboHercules, a Nehalem EX equipped PC should be able to give a performance of 3.200 MIPS by software emulation.
Thus there is no legal way to run z/OS
1.6 (or higher), DB2
V8 (or higher), z/TPF, or z/VSE 4.1 (or higher) on PC-based machines except for IBM PartnerWOrld Independent Software Devloeprs (ISVs) who can use a feature called [System z Personal Development Tool zPDT based on a Linux emulation. IBM Rational application developers can obtain zPDT through the licensing of Rational Developer for System z Unit Test (RDz UT).
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
in the 1980s, IBM
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...
and other vendors have created PC-based IBM-compatible mainframes which are compatible with the larger IBM mainframe computer
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...
s. For a period of time PC-based mainframe-compatible systems had a lower price and did not require as much electricity or floor space. However, they sacrificed performance and were not as dependable as mainframe-class hardware. These products have been popular with mainframe developers, in education and training settings, for very small companies with non-critical processing, and in certain disaster relief roles (such as field insurance adjustment systems for hurricane relief).
Background
Up until the mid-1990s, mainframes were very large machines that often occupied entire rooms. The rooms were often air conditioned and had special power arrangements to accommodate the three-phase electric powerThree-phase electric power
Three-phase electric power is a common method of alternating-current electric power generation, transmission, and distribution. It is a type of polyphase system and is the most common method used by grids worldwide to transfer power. It is also used to power large motors and other heavy loads...
required by the machines. Modern mainframes are now physically comparatively small and require little or no special building arrangements.
System/370
IBM had demonstrated use of a mainframe instruction set in a desktop computer with the IBM 5100IBM 5100
The IBM 5100 Portable Computer was a portable computer introduced in September 1975, six years before the IBM PC. It was the evolution of a prototype called the SCAMP that was developed at the IBM Palo Alto Scientific Center in 1973. In January 1978 IBM announced the IBM 5110, its larger cousin,...
. This product used microcode to execute many of the System/370's processor instructions, so that it could run a slightly modified version of IBM's APL mainframe program interpreter.
Origins
"The VM/PC Software traces it's origins to an activity initiated at the IBM Cambridge Scientific Center to build a prototype CMS workstation, This prototype was called CnS(Cambridge nano-System).
Personal Computer XT/370
In October, 1983, IBM announced the IBM Personal Computer XT/370. This was an XT with three custom 8-bit cards. The processor card (370PC-P), contained two modified Motorola 68000 chips,and an 8087 modified to emulate the S/370 floating point instructions. The second card (370PC-M), which connected to the first with a unique card back connector contained 512Kib of memory. The third card (PC3277-EM), was a 3270 terminal emulator required to download system software from the host mainframe. The XT/370 computer booted into DOS, then ran the VM/PC Control Program. The card's memory space added additional system memory, so the first 256Kib (motherboard) memory could be used to move data to the 512kb expansion card. The expansion memory was dual ported, and provided an additional 384Kb to the XT Machine bringing the total ram on the XT side to 640 kb. The memory arbitrator could bank switch the second 128 kb bank on the card to other banks, allowing the XT 8088 processor to address all the RAM on the 370PC-M card.Personal Computer AT/370
On April 2, 1986, IBM announced the IBM Personal Computer AT/370, with similar cards as for the XT/370 and updated software, to support both larger hard disks, and DMA transfers from the 3277 card to the AT/370 Processor card. The system was almost 60% faster than the XT/370.IBM 7437
As of November 1988, IBM was shipping a workstation version of the System/370 hardware intended to run IBM's VM/SPVM
VM may stand for:In business*VM Motori, a diesel engine manufacturer*Vauxhall Motors, a British car maker*Viaggio Air *Virgin Media, a cable provider in the United Kingdom*Virgin Mobile, a mobile phone service...
operating system. It was a freestanding tower, that connected to a MCA
Micro Channel architecture
Micro Channel Architecture was a proprietary 16- or 32-bit parallel computer bus introduced by IBM in 1987 which was used on PS/2 and other computers through the mid 1990s.- Background :...
card installed in a PS/2
IBM Personal System/2
The Personal System/2 or PS/2 was IBM's third generation of personal computers. The PS/2 line, released to the public in 1987, was created by IBM in an attempt to recapture control of the PC market by introducing an advanced proprietary architecture...
Model 60, 70, or 80.
Personal/370
Later, IBM introduced the Personal/370 (aka P/370), a single slot 32-bit MCAMicro Channel architecture
Micro Channel Architecture was a proprietary 16- or 32-bit parallel computer bus introduced by IBM in 1987 which was used on PS/2 and other computers through the mid 1990s.- Background :...
card that can be added to a PS/2
IBM Personal System/2
The Personal System/2 or PS/2 was IBM's third generation of personal computers. The PS/2 line, released to the public in 1987, was created by IBM in an attempt to recapture control of the PC market by introducing an advanced proprietary architecture...
or RS/6000
RS/6000
RISC System/6000, or RS/6000 for short, is a family of RISC and UNIX based servers, workstations and supercomputers made by IBM in the 1990s. The RS/6000 family replaced the IBM RT computer platform in February 1990 and was the first computer line to see the use of IBM's POWER and PowerPC based...
computer to run System/370 OSs (like MUSIC/SP
MUSIC/SP
MUSIC/SP was developed at McGill University in the 1970s from an early IBM time-sharing system called RAX...
, VM
VM (operating system)
VM refers to 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 first version, released in 1972, was VM/370, or officially Virtual Machine Facility/370...
, VSE
VSE
z/VSE is an operating system for IBM mainframe computers, the latest one in the DOS/360 lineage, which originated in 1965. It is less common than prominent z/OS and is mostly used on smaller machines. Primary z/VSE development occurs in IBM's Böblingen labs in Germany.-Overview:DOS/360 originally...
) parallel to OS/2
OS/2
OS/2 is a computer operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2," because it was introduced as part of the same generation change release as IBM's "Personal System/2 " line of second-generation personal...
(in PS/2) or AIX
AIX operating system
AIX AIX AIX (Advanced Interactive eXecutive, pronounced "a i ex" is a series of proprietary Unix operating systems developed and sold by IBM for several of its computer platforms...
(in RS/6000) supporting multiple concurrent users. It is a complete implementation of the S/370 Processor including a FPU
Floating point unit
A floating-point unit is a part of a computer system specially designed to carry out operations on floating point numbers. Typical operations are addition, subtraction, multiplication, division, and square root...
co-processor and 16 MB memory. Management and standard I/O channels are provided via the host OS/hardware. An additional 370 channel card can be added to provide mainframe-specific I/O such as 3270 local control units, 3400/3480 tape drives or 7171 protocol converters.
System/390
As IBM's mainframes became much more powerful and had bigger instruction sets, IBM's PC-related products evolved as well.S/390 Processor Card
An important goal in the design of the S/390 Processor Card was complete compatibility with existing mainframe operating systems and software. The processor implements all of the ESA/390 and XA instructions which prevents the need for instruction translation. There are three generations of the card:- The original S/390 Processor Card incorporated 32MB of dedicated memory, with optional 32MB or 96MB daughter cards, for a combined total of 64MB or 128MB of RAM. The processor was officially rated at 4.5 MIPS. It was built to plug into a MicroChannelMicro Channel architectureMicro Channel Architecture was a proprietary 16- or 32-bit parallel computer bus introduced by IBM in 1987 which was used on PS/2 and other computers through the mid 1990s.- Background :...
host system. - The second version was built for a PCIPeripheral Component InterconnectConventional PCI is a computer bus for attaching hardware devices in a computer...
host system. It included 128 MB of dedicated memory as standard, and was still rated at 4.5 MIPS. - The third version, referred to as a P/390E card (for Enhanced), included 256 MB of dedicated memory and was rated at 7 MIPS. It, too, was built for a PCIPeripheral Component InterconnectConventional PCI is a computer bus for attaching hardware devices in a computer...
host system. There was an extremely rare (possibly only ever released as pre-production samples) 1 GB memory version of the P/390E card.
R/390
R/390 was the designation used for the expansion card used in an IBM RS/6000 server. The original R/390 featured a 67 or 77 MHz POWER2POWER2
The POWER2, originally named RIOS2, is a processor designed by IBM that implemented the POWER instruction set architecture. The POWER2 was the successor of the POWER1, debuting in September 1993 within IBM's RS/6000 systems. When introduced, the POWER2 was the fastest microprocessor, surpassing the...
processor and 32 to 512 MB of RAM, depending on the configuration. The MCA
Micro Channel architecture
Micro Channel Architecture was a proprietary 16- or 32-bit parallel computer bus introduced by IBM in 1987 which was used on PS/2 and other computers through the mid 1990s.- Background :...
P/390 expansion card can be installed in any MCA
Micro Channel architecture
Micro Channel Architecture was a proprietary 16- or 32-bit parallel computer bus introduced by IBM in 1987 which was used on PS/2 and other computers through the mid 1990s.- Background :...
RS/6000 system, while the PCI
Peripheral Component Interconnect
Conventional PCI is a computer bus for attaching hardware devices in a computer...
P/390 card can be installed in a number of early PCI
Peripheral Component Interconnect
Conventional PCI is a computer bus for attaching hardware devices in a computer...
RS/6000s; all such configurations are referred to as an R/390. R/390 servers need to run AIX version 4 as the host operating system.
P/390
P/390 was the designation used for the expansion card used in an IBM PC Server and was less expensive than the R/390. The original P/390 server was housed in an IBM PC Server 500 and featured a 90 MHz Intel Pentium processor for running OS/2. The model was revised in mid-1996 and rebranded as the PC Server 520, which featured a 133 MHz Intel Pentium processor. Both models came standard with 32MB of RAM and were expandable to 256MB. The PC Server 500 featured eight MCA expansion slots while the PC Server 520 added two PCIPeripheral Component Interconnect
Conventional PCI is a computer bus for attaching hardware devices in a computer...
expansion slots and removed two MCA slots.
S/390 Integrated Server
The S/390 Integrated Server (aka S/390 IS) is a mainframe housed in a comparably small case (HxWxD are 82 x 52 x 111 cm). It became available from November 1998. It is intended for customers who do not require the I/O bandwidth and performance of the S/390 Multiprise 3000Multiprise 3000
As of late 2006, IBM's Multiprise 3000, having the product number 7060, is physically the smallest mainframe, introduced in 1999 and still in common use . It uses a similar case as the S/390 Integrated Server, which was introduced about one year earlier. The Multiprise 3000 is unusual because it...
(which has the same size). Only 256 MB of ECC Memory and a single CMOS main processor (performance about 8 MIPS) are used; the S/390 CPU used in the Integrated Server is in fact the P/390 E-card. A Pentium II
Pentium II
The Pentium II brand refers to Intel's sixth-generation microarchitecture and x86-compatible microprocessors introduced on May 7, 1997. Containing 7.5 million transistors, the Pentium II featured an improved version of the first P6-generation core of the Pentium Pro, which contained 5.5 million...
is used as IOSP (I/O Service Processor). It supports four ESCON
ESCON
ESCON is a data connection created by IBM, and is commonly used to connect their mainframe computers to peripheral devices such as disk storage and tape drives. ESCON is an optical fiber, half-duplex, serial interface. It originally operated at a rate of 10 Mbyte/s, which was later increased to...
and to four parallel channels. Standard PCI and ISA slots are present. A maximum of 255 GB internal harddisks are supported (16x 18GB HDs, with 2x HDs for redundancy). The supported OSs are OS/390, MVS/ESA, VM/ESA and VSE/ESA.
Fujitsu PC-based mainframes
Fujitsu offers two PC-compatible systems that make up the lower end of Fujitsu's S/390-based BS2000BS2000
BS2000 is a mainframe computer operating system developed by Fujitsu Technology Solutions.Unlike other mainframe systems, BS2000/OSD provides exactly the same user and programming interface in all operating modes and regardless of whether it is running natively or as a guest system in a virtual...
mainframe product line. The SQ100 is the slower configuration, running on dual-core Xeon E7220 processors, and is capable of up to 200RPF of performance. The SQ200 was introduced more recently, uses 6-core Xeon X7542 processors, and has performance of up to 700RPF. All x86-based BS2000 mainframes can run Linux or Windows in separate partitions. Fujitsu also continues to make custom S/390-native processors and mainframe hardware for the high end of its BS2000 line.
z/Architecture and today
Since the late 1990s, PC processors have become fast enough to perform mainframe emulation without the need for a peripheral card. One of the most popular PC-based IBM-compatible mainframe products as of 2006 is Fundamental Software's FLEX-ES product. FLEX-ES emulates both System/390 (ESA/390) and z/Architecture. While FLEX-ES is capable of running on most PC hardware, the licensing agreement prohibits it. FLEX-ES must run on the machine with which it was sold; in the past, this included Compaq Proliant and HP servers, but today this is nearly always an approved IBM xSeriesXseries
Xseries or xSeries may refer to:* Nokia Xseries, a family of mobile phones.* IBM System x, previously eServer xSeries.* X-Series, a mobile broadband offering from 3.* X , a space combat and trading video game series....
server or a ThinkPad
ThinkPad
ThinkPad is line of laptop computers originally sold by IBM but now produced by Lenovo. They are known for their boxy black design, which was modeled after a traditional Japanese lunchbox...
laptop.
Another popular emulator is the open source Hercules emulator, which has been in development since 1999 and emulates the System/370, System/390, and z/Architecture instruction sets. While Hercules cannot legally run modern IBM operating systems, earlier System/370 operating systems are in the public domain and can be legally run on Hercules. According to Tom Lehmann, cofounder of TurboHercules, a Nehalem EX equipped PC should be able to give a performance of 3.200 MIPS by software emulation.
Thus there is no legal way to run z/OS
Z/OS
z/OS is a 64-bit operating system for mainframe computers, produced by IBM. It derives from and is the successor to OS/390, which in turn followed a string of MVS versions.Starting with earliest:*OS/VS2 Release 2 through Release 3.8...
1.6 (or higher), DB2
IBM DB2
The IBM DB2 Enterprise Server Edition is a relational model database server developed by IBM. It primarily runs on Unix , Linux, IBM i , z/OS and Windows servers. DB2 also powers the different IBM InfoSphere Warehouse editions...
V8 (or higher), z/TPF, or z/VSE 4.1 (or higher) on PC-based machines except for IBM PartnerWOrld Independent Software Devloeprs (ISVs) who can use a feature called [System z Personal Development Tool zPDT based on a Linux emulation. IBM Rational application developers can obtain zPDT through the licensing of Rational Developer for System z Unit Test (RDz UT).
External links
- P/390 and R/390 with OS/390: An Introduction (IBM Redbook)
- P/390, R/390, S/390 Integrated Server: OS/390 New User's Cookbook (IBM Redbook)
- S/390 Integrated Server - Hardware Announcement; September 8, 1998
- VM/ESA Performance on P/390 and R/390 PC Server 520 and RS/6000 591
- Detail pictures of a PC Server 500, on the private website of Alfred Arnold
- Detail pictures of a S/390 IS (incl. screenshot of console), on the private website of Michael J. Ross
- P/390 Information at '9595 Ardent Tool of Capitalism'
- IBM PC Server System/390 FAQ at '9595 Ardent Tool of Capitalism'
- zPDT: Introduction and Reference. (IBM Redbook)
- zPDT: User's guide (IBM Manual)
- zPDT worldwide distributor
- zPDT for Rational Developer for System z Unit Test