IBM System/38

System/38 is a mini-computer company IBM. The system was announced in 1978 and first delivered August 1979. The System/38 (also S38, System38 ) was developed by Frank Soltis at the IBM lab in Rochester. It is designed as a multi-user and multi-threaded system for commercial applications.

It was intended as a successor to the IBM System / 3 and had an advanced object -based architecture. According to a market analysis in 1983, 69 percent of customers used before the IBM System / 3 The goal is to move these customers to transition to the new computer has been achieved. The System/38 was replaced in 1988 by the successor to the AS/400 system, which now operates under the name of system i.

Operating system and database

The System/38 was determined with a relational database for dialog processing. The system also had a good performance in batch processing, such as day-end closing, inventory and the like.

The operating system, called CPF system control program was tailored to this machine and hardware. The operation was carried out via the control language program CL. There were originally shipped with only two programming languages. These were COBOL and RPG III. Later, PL / 1 and BASIC joined as the programming language. The relational database was built into the operating system.

Hardware independence

The goal was to build a computer, in which the programmer from the hardware were independent. That is to say that the hardware and its interface could be exchanged to the applications without the programs needed to be recompiled. This was by no means self-evident. For a multi- layer model has been developed.

Memory and memory addressing

The System/38 had a memory of 512K, 768K or 1024K (Model 3XX and 5XX ) respectively 1280K or 1536K (Model 5XX ). The computer could address a 48-bit address space, and has all the memory ( RAM and plates ) have in an address space.

User management and permissions

The system was multi-user and had thus a user management. An authorization object architecture enabled the assignment of rights at the object level. This could build an authorization system that determined exactly in what way a program, file or other object could be used by a user.

Input and output devices

As a screen devices twinax terminals were used. There were defaults to 12 and a maximum of 40 IBM 5250. Twinax was only used by IBM. The Twinaxsystem allowed seven devices on a line in series. There was twinax Twinax displays and printers. Furthermore, data could be read also on 8-inch floppy disks. For example, the operating system was delivered on multiple disks. The backup of the system was also carried out on diskettes. These usually floppy magazines were used. Each of these magazines could include 10 disks.