【Toshiba】 TOPS

"TOPS" was the OS for the TOSBAC-3400 series of general-purpose computers developed by Toshiba, and its primary purpose was scientific and engineering computing. The TOPS series included diverse variations that met system configurations and functional evolutions ranging from TOPS-1, capable of sequential job execution based on a magnetic drum, to TMS, capable of multi-dimensional processing based on a magnetic disk.

TOPS-1: This was an OS capable of sequential job execution based on a magnetic drum/paper tape reader in a configuration called "A system" for TOSBAC-3400 models 20 and 30, and was developed through cooperation between Kyoto University and Toshiba in 1964. It was based on the technology for KT-FORTRAN and FORTRAN monitors prototyped in cooperation between both parties prior to TOPS-1. The functions of TOPS-1 were configured as follows.

Figure 1 Configuration of functions of TOPS-1

TOPS-2

This was an OS capable of sequential job execution based on a magnetic drum/paper tape reader in a configuration called “B system” for models TOSBAC-3400 20 and 30, and its development was completed in 1965. The functions of TOPS-2 were configured as follows:

Figure 2 Configuration of functions of TOPS-2

TOPS-3

This was an OS based on a magnetic drum using a card reader in a configuration called "C system" for TOSBAC-3400 models 20 and 30, and its development was completed in 1966. The purpose of developing TOPS-3 was to compete against the OS of IBM7090.
　In TOPS-3, sequential job execution was basically performed. However, inputting and outputting to/from low-speed devices, such as a card reader, card puncher, paper tape reader, paper tape puncher and line printer, were performed by way of a magnetic drum. In other words, a user application was executed through constant replacement of the inputting/outputting to/from these low-speed devices by the execution on the magnetic drum such as [low-speed device] <-> [IOEX] <-> [magnetic drum] <-> [application], instead of direct execution of the inputting/outputting ([I/O device] <-> [application]). Data transfer between the magnetic drum and the actual I/O device was executed by a data transmission routine that operated under control of IOEX, which was an OS module. This shortened the turnaround time of the application. In addition, since the data transmission routine was executed in parallel to the user application, throughput was improved. The functions of TOPS-3 were configured as follows:

Figure 3 Configuration of functions of TOPS-3

TOPS-4

TOPS-4 was a magnetic tape-based OS for TOSBAC-3400 model 40, developed by Toshiba in 1966 to achieve continuous job execution. It was developed by referring to FORTRAN system monitor IBSYS of IBM7090, which was a typical large-scale computer at that time. Whereas it was impossible with TOPS-1 to TOPS-3 to configure a single executable program by linking together programs written in different languages, TOPS-4 realized that configuration. In 1967, the OS was improved to a magnetic disk-based OS, and a TSS system was also developed. The functions of TOPS-4 were configured as follows:

Figure 4 Configuration of functions of TOPS-4

TOPS-11

TOPS-11 was a magnetic disk-based OS (using a removable magnetic disk pack) for TOSBAC-3400 models 20 and 30 developed by Toshiba in 1967. On the magnetic disk were placed a system library, a user library and a working file for data. Inputting of a program or data was executed from a card reader and a paper tape reader, and a paper tape was used to save the generated binary program. In 1968, the OS was improved to a magnetic disk-based OS for models 21 and 31, which were IC-based computers.
　The minimum and maximum configurations of hardware for using TOPS-11 were as follows:

　Main unit; core memory 8 k words (24 bits/word); magnetic disk pack (1 unit);
　paper tape reader (1 unit); console typewriter (1 unit)

　Main unit; core memory 16 k words; magnetic disk pack (2 units); other I/O devices

The functions of TOPS-11 were configured as follows:

Figure 5 Configuration of functions of TOPS-11

TOPS-14

TOPS-14 was a magnetic disk-based OS (using a removable magnetic disk pack) for TOSBAC-3400 model 41, which was developed by Toshiba in 1968 by enhancing the functions of TOPS-4. It provided a full-scale multiprogramming function and a file access method that effectively used random accessibility of the magnetic disk. There were four methods of accessing files on the magnetic disk: any combination of whether or not to queue continuous input/output requests, and whether or not to create an index of records for improved accessibility

　The minimum and maximum configurations of the hardware for using TOPS-14 were as follows:

　Main unit; memory 32 k words (24 bits/word); magnetic disk pack (1 unit);
　card reader (1 unit), and console typewriter (1 unit)

　Main unit; core memory 64 k words; magnetic disk pack (3 units);
　magnetic tape device (6 units), card reader (1 unit); and console typewriter (1 unit)

The functions of TOPS-14 were configured as follows:

Figure 6 Configuration of functions of TOPS-14

TMS

TMS was an OS based on a magnetic disk for TOSBAC-3400 models 41 and 51 developed by Toshiba in 1970, and enabled coexistence of local batch processing and online real-time processing.
　The size of the memory resident area of TMS was approximately 14 k words, and the OS area also required at least 2 k words for the transient area for loading TMS modules from the magnetic disk to the storage as necessary, translating to 16 k words in total. This transient area was designed to be automatically expanded if the user memory had room, and to allow a module that had been loaded from the magnetic disk to be retained on the storage whenever possible. If it became necessary to have user memory because the size of the program to be executed was large or there was an increase in the number of programs to be executed simultaneously, the transient areas were sequentially released. The minimum configuration required for executing applications on a system installed with TMS was 64 k words (24 bits/word) in memory and two disks (2,400 k words).

Figure 7 Configuration of functions of TMS

Mainframe OS

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