The following outlines the history of the operating systems (OS) for Fujitsu’s mainframe computers up to 1990.
（1）Software for Fujitsu’s early computers
Fujitsu did not provide software for its computers until 1963, when it provided a loader, IOCS (Input Output Control System), FAST (FORTRAN compiler), assembler and SORT program as the software for the large general-purpose computer FACOM 222.
Fujitsu did not provide software for its computers until 1963, when it provided a loader, IOCS (Input Output Control System), FAST (FORTRAN compiler), assembler and SORT program as the software for the large general-purpose computer FACOM 222.
（2）Control programs MCP (Master Control Program) I, II and III for medium-scale computers of the FACOM 230 series
The company developed control programs MCP I and MCP II for batch processing for the medium-scale general-purpose computers FACOM 230-20 and FACOM 230-30 in 1965 and 1966, respectively, and MCP III, which realized small-scale real-time processing, in 1967. MCP II was the company’s first medium-scale general-purpose OS to realize multiprogramming.
The company developed control programs MCP I and MCP II for batch processing for the medium-scale general-purpose computers FACOM 230-20 and FACOM 230-30 in 1965 and 1966, respectively, and MCP III, which realized small-scale real-time processing, in 1967. MCP II was the company’s first medium-scale general-purpose OS to realize multiprogramming.
（3） Control programs MONITOR II, III, IV, V, VI and VII for large-scale computers of the FACOM 230 series
Fujitsu commercialized OS MONITOR II for the large-scale general-purpose computer FACOM 230-50 in 1966 based on its success with the FONTAC project of the Ministry of International Trade and Industry. MONITOR II led the world in adopting a dynamic relocation method. Subsequently, in 1968, the company developed MONITOR III and MONITOR IV, which had enhanced functions.
Next, Fujitsu developed MONITOR V (completed in 1968) and MONITOR VI (completed in 1974) as the OSs for the large-scale general-purpose computer FACOM 230-60, and MONITOR VII (completed in 1974) as the OS for the super-large general-purpose computer FACOM 230-75. MONITOR V led the world in supporting a symmetrical, tightly coupled multiprocessor system, and was the company’s first OS to provide a TSS function.
Fujitsu commercialized OS MONITOR II for the large-scale general-purpose computer FACOM 230-50 in 1966 based on its success with the FONTAC project of the Ministry of International Trade and Industry. MONITOR II led the world in adopting a dynamic relocation method. Subsequently, in 1968, the company developed MONITOR III and MONITOR IV, which had enhanced functions.
Next, Fujitsu developed MONITOR V (completed in 1968) and MONITOR VI (completed in 1974) as the OSs for the large-scale general-purpose computer FACOM 230-60, and MONITOR VII (completed in 1974) as the OS for the super-large general-purpose computer FACOM 230-75. MONITOR V led the world in supporting a symmetrical, tightly coupled multiprocessor system, and was the company’s first OS to provide a TSS function.
（4）Medium-scale OSs and large-scale OSs for the FACOM 230-5 series and the FACOM 230-8 series
In 1968, Fujitsu announced BOS for batch processing and ROS for real-time processing for the medium-scale general-purpose computers FACOM 230-25 and FACOM 230-35, and OS 45 (later renamed OSII) for the large-scale general-purpose computers FACOM 230-45S and FACOM 230-55.
In 1973, the company announced medium-scale OS BOS/VS and large-scale OS OSII/VS, which realized virtual memory, for the FACOM 230-8 series. OSII/VS was Fujitsu’s first OS to realize multiple virtual memory.
In 1968, Fujitsu announced BOS for batch processing and ROS for real-time processing for the medium-scale general-purpose computers FACOM 230-25 and FACOM 230-35, and OS 45 (later renamed OSII) for the large-scale general-purpose computers FACOM 230-45S and FACOM 230-55.
In 1973, the company announced medium-scale OS BOS/VS and large-scale OS OSII/VS, which realized virtual memory, for the FACOM 230-8 series. OSII/VS was Fujitsu’s first OS to realize multiple virtual memory.
（5）OSIV/F4, OSIV/X8 and OSIV/F2 for FACOM M series, which adopted unified architecture
Fujitsu developed three OSs for the FACOM M general-purpose computers: super-large general-purpose OS OSIV/F4, large-scale general-purpose OS OSIV/X8 with a high performance-to-price ratio, and medium-scale general-purpose OS OSIV/F2, which was optimal for medium-scale business operations.
Thereafter, various functional enhancements, including support for new hardware, were implemented for these three OSs, and super-large general-purpose OS OSIV/F4 evolved into OSIV/F4 MSP and OSIV/MSP (MSP-EX), while large-scale general-purpose OS OSIV/X8 evolved into OSIV/X8 FSP and OSIV/XSP. Medium-scale general-purpose OS OSIV/F2 first evolved into OSIV/ESP V2 and OSIV/ESPIII, and then was integrated with OSIV/XSP. In the M series OSs, integrated online database (DB/DC) products were provided from the initial stage.
Fujitsu developed three OSs for the FACOM M general-purpose computers: super-large general-purpose OS OSIV/F4, large-scale general-purpose OS OSIV/X8 with a high performance-to-price ratio, and medium-scale general-purpose OS OSIV/F2, which was optimal for medium-scale business operations.
Thereafter, various functional enhancements, including support for new hardware, were implemented for these three OSs, and super-large general-purpose OS OSIV/F4 evolved into OSIV/F4 MSP and OSIV/MSP (MSP-EX), while large-scale general-purpose OS OSIV/X8 evolved into OSIV/X8 FSP and OSIV/XSP. Medium-scale general-purpose OS OSIV/F2 first evolved into OSIV/ESP V2 and OSIV/ESPIII, and then was integrated with OSIV/XSP. In the M series OSs, integrated online database (DB/DC) products were provided from the initial stage.
（6）Virtual machine control OSs AVM, AVM/EF and AVM/EX
In 1980, Fujitsu shipped AVM (Advanced Virtual Machine), which was a virtual machine control OS for mainframe computers. AVM/EF (announced in 1982), which utilized the high-speed VM mechanism of the hardware, and AVM/EX (announced in 1989), which utilized the extended VM mechanism of the hardware, both developed later, substantially reduced the overheads of the virtual machines, and provided functions for efficiently operating multiple OSs.
In 1980, Fujitsu shipped AVM (Advanced Virtual Machine), which was a virtual machine control OS for mainframe computers. AVM/EF (announced in 1982), which utilized the high-speed VM mechanism of the hardware, and AVM/EX (announced in 1989), which utilized the extended VM mechanism of the hardware, both developed later, substantially reduced the overheads of the virtual machines, and provided functions for efficiently operating multiple OSs.
（7）UNIX UTS/M and UXP/M for mainframe computers
Fujitsu announced UTS/M, which was developed through transplanting UNIX system V release 2.0 to its M series in 1982, and UXP/M, which complied with UNIX system V release 4, in 1990, allowing UNIX systems to use the high processing capacities of the company’s mainframe computers and their various peripherals.
Fujitsu announced UTS/M, which was developed through transplanting UNIX system V release 2.0 to its M series in 1982, and UXP/M, which complied with UNIX system V release 4, in 1990, allowing UNIX systems to use the high processing capacities of the company’s mainframe computers and their various peripherals.