System / 36
The system / 36 , short form / 36 , is a computer model from IBM . The system is a multi-user and multi-threaded system.
history
The / 36 was developed on the basis of the / 34 system. It was presented in May 1983. There were models for small companies (also referred to as so-called department computers) up to models for larger expansion stages. The / 36 was characterized by its ease of use and its high level of reliability at the time. In addition to the / 36 system, the / 38 system was also offered by IBM .
Models and hardware
The / 36 was released as Model 5360 and 5362. The models 5360 and 5362 had up to 7 MB main memory, up to 1.4 GB disk space and a disk magazine drive for 20 diskettes with 8 "diameter (10 disks each in a magazine) as well as a single feed for 3 diskettes. The 14" magnetic disks Weighing a few dozen kilograms, for example, had a capacity of 320 MB at a price of around 30,000 DM in the mid-1980s. The difference between the 5360 and the 5362 was the expanded housing, which offered greater connection options for magnetic disks.
A smaller 5363 followed later, to which up to 28 units could be connected locally. This model was later marketed as AS / Entry 5363 to represent a certain transition to the successor model AS / 400 .
The address space was 16 bits.
The S / 36 had a control panel on which error messages from the operating system (so-called SRC = System Reference Codes) could be read and answered if necessary. Furthermore, special functions could be carried out here and the IPL (Initial Program Load) could be carried out.
The terminals were connected via twinaxial cables . A maximum of seven devices could be connected in one line, which were connected in series one after the other. Each terminal had an entrance and exit. The end device had to be terminated. Six of these lines could be connected to a controller . A maximum of 72 local workstations could be connected. Dial-up adapters, in conjunction with the 5294 control units and a data connection line, enabled remote data processing.
When the era of the PCs began, connection cards were offered for them that provided what is known as 5250 emulation . This enabled a PC to work as a terminal on the / 36 system.
From 1985, magnetic tape cassettes and devices with capacities from a few dozen to a few hundred Mbytes were offered for faster data backup.
Operating system and programming
The SSP operating system had a general menu control that made the / 36 much more user-friendly than the / 38 . You could choose commands from a menu structure or select parameters using function keys, which made complicated functions easier for not so experienced administrators. The system / 36 was programmed using OCL (Operating Control Language) as the control language and BASIC , Cobol or RPG as the programming language. The SEU (Source Entry Utility) and SDA (Screen Design Aid) tools were available for this. Furthermore, a help called POP (Programmer and Operator Productivity Aid) was offered, which made it possible to call up all functions via menus.
In practice, it was often necessary to carry out a compress , similar to today's defragmentation on Windows PCs. The areas of the hard disk that had become free were combined into larger blocks so that the operating system could have this space again, since new data to be written could only be written in suitable blocks. This often took several hours.
Detachment
The high maintenance fees and the limited expandability of the S / 36 then led to the development of the successor model AS / 400 in 1988. The system / 36 continued to run for a few years in predominantly medium-sized companies and even survived the turn of the millennium while still in operation.
