MONITOR VII was the operating system (hereinafter “OS”) for Fujitsu’s large general-purpose computer FACOM 230-75, and MONITOR VI was the OS for super-large general-purpose computer FACOM 230-60. These two OSs were developed around the same time, and they substantially increased the processing capacity and reliability of MONITOR V while maintaining compatibility with it.
 The following describes the background to development of the large general-purpose OSs MONITOR VII and VI, and the features of MONITOR VII and VI.

1.Background to development of MONITOR VII and MONITOR VI

 In line with the start of development of the super-large general-purpose computer FACOM 230-75, development of a dedicated OS was also planned. This OS needed to meet the market requirements for upward compatibility with MONITOR V, dramatically increase in processing capacity, expansion of applications, enhancement of the online processing function and realization of a high-reliability system.
 Meanwhile, expansion of the areas to which computers were being applied and increase of complexity of operations led to OSs becoming larger and more complex. This made it difficult to overcome system bugs, which were a factor in limiting extendability of functions.
 To solve this problem, Fujitsu researched ways of meeting the above-mentioned requirements. This resulted in deciding to introduce a new concept of independent sub monitors for the respective functions, and to redesign the whole control program.
 Although this new OS was planned as an OS for FACOM 230-75, it was also essential to provide same functions as that of the new OS for FACOM 230-60, which had been already provided and was in operation. Consequently, the company provided MONITOR VII as the OS for FACOM 230-75, and MONITOR VI as the OS for FACOM 230-60. The functions of MONITOR VII were the same as those of MONITOR VI, except for those functions that were dependent on the hardware of FACOM 230-75 and the batch function was completed in March 1974, and the TSS function in April 1975. The array processor control function for FACOM 230-75 APU was added to MONITOR VII in August 1977.
2.Features of MONITOR VII and MONITOR VI

 The following describes the features of MONITOR VII. The features of MONITOR VI were identical to those of MONITOR VII except for those items specific to FACOM 230-75.

(1) Compatibility with MONITOR V
 The FACOM 230-75 hardware had upward compatibility with the previous model FACOM 230-60, and was capable of running all programs developed for FACOM 230-60.
 For MONITOR VII, Fujitsu adopted the same system macro instructions that defined the interface between the control program and the processing program as were used in MONITOR V, and added new functions, and MONITOR VII consequently achieved upward compatibility with MONITOR V.
(2) Increased processing capacity
 The CPU speed of FACOM 230-75 was 5 to 7 times faster than that of its predecessor FACOM 230-60. In addition to the CPU speed, the processing capacity of FACOM 230-75 significantly exceeded that of MONITOR VII as a result of enhancements, including: 1) expansion of the main memory capacity from 256K words to 1,024K words, 2) acceleration of the I/O processing using a block multiplexer channel (BMC) and magnetic disk pack FACOM 477K, 3) increase in the number of calculation registers from 1 set to 4 sets, 4) addition of instructions for clerical calculations, and 5)addition of hardware macro instructions into which frequently used sequences of instructions of the control program were coded.
(3) Enhanced online processing
 For MONITOR VII, Fujitsu provided ETAM (Extended Telecommunication Access Method) as a communication control function for terminals. ETAM enabled integrated control of terminals and development of online processing programs in COBOL. In addition, the company provided COP (online COmmon Package), which was intended for standardization of online system designing, independence of business application programs, and standardization of communication line processing, for large-scale online systems. Previously, online business application programs were written in assembler languages. Provision of the online high-level language COPTRAN (COP Translator) facilitated the online application program development.
(4) Diversified processing modes
 MONITOR VII was designed to be adaptable across all processing modes.
1) Batch processing (diversified inputting tools, increased efficiency with job class function or the like, labor-saving function)
2) Remote batch processing (use of high-speed communication line, secrecy protection through integrated user management throughout the system, etc.)
3) Interactive processing (provision of new time-sharing system CPS (Conversational Programming System), interactive remote batch processing)
4) Online processing
5) Network system (provision of multiple computer systems connected through CCA: Channel to Channel Adapter)
(5) Labor saving
 Operation of a super-large computer involved elements requiring a high level of judgment and relatively simple operations related to inputting and outputting. In particular, the latter required considerable labor due to the increase in processing capacity of computers. In MONITOR VII, labor-saving functions were provided.
 For MONITOR VII, the company provided a batch-station function and a demand print function. These functions enabled the user to directly engage in job inputting/outputting in a self-service manner, instead of an operator at the computer center.
 Previously, handling of magnetic tapes accounted for a large proportion of the work performed by a center operator. The magnetic tape units FACOM 610A and 611A, which were equipped with auto-loading mechanism and AVR (automatic volume recognition) function, automatically read the volume serial number of tape made the tape ready for use.
(6) High-reliability system
 The MONITOR VII system was a highly reliable system realized through organic combination of the RAS functions of the hardware of FACOM 230-75 and software functions under the concept of FRS (Failure Recognition and Support).
 Representative functions included: 1) periodic diagnosis for early detection of failure (PADIA: Patrol Diagnosis Program), 2) automatic recovery through hardware including the CPU and the main memory, and functions of software-based recovery/separation of I/O devices, 3) diagnosis function executable without stopping the system (OLTE: Online Test Program), 4) configuration control function that allowed detaching the main devices (in main unit) and the I/O devices from the system and incorporating them into the system, 5) collection and analysis of failure information (error logging), and 6) system file duplexing function.
(7) Multiple computer systems
 Although FACOM 230-75 was a super-large computer, the scope of system uses was expanded to the extent that all processing demands could not be met by a single computer. MONITOR VII enabled information transmission and information sharing between multiple computer systems by providing a computer network function for connecting multiple computer systems via a high-speed transmission device and a function for sharing files between systems.