IBM System/36
The System/36, short form / 36, is a computer model of the company IBM. The system is a multi-user and multi-threaded system.
History
On the basis of the Systems/34 / 36 has been developed. It was presented in May 1983. There were models for small companies (also referred to as so-called mainframes ) to models of larger expansion levels. The simple operation and high reliability in those days recorded from the / 36. In addition to the System/36 was IBM parallel the System/38 offered.
Models and hardware
The / 36 was brought out as a model 5360 and 5362. The models 5360 and 5362 had up to 7 MB of memory, up to 1.4 GB of disk and a floppy magazine drive for 20 disks with 8 "diameter ( each with 10 disks in a magazine ), and a single-feed for 3 disks. The 14" magnetic disks had a weight of several dozen kilograms for example a capacity of 320 MB at a price mid-80s of about 30.000, - DM the difference between the 5360 and the 5362 were in an extended housing that offered more connectivity options for magnetic disks.
Later followed a smaller 5363, to which one could connect locally up to 28 units. This model was later identified as AS / Entry 5363 sold to represent a certain transition to the successor AS/400.
The address space was 16 bit.
Could be the S/36 had a control console at the error messages from the operating system ( so-called SRC = System Reference Codes ) read and possibly answer. Furthermore, this special functions could be performed as well as the IPL (Initial Program Load ) are performed.
The terminals were connected to the twinax cables. Here more than seven devices could be connected in a string, which were connected in series one after the other. To this end, each terminal had an input and output. The terminal had to be terminated. On a controller could be connected six of these lines. Maximum were 72 local jobs are connected. Dial-Up Adapter enabled in conjunction with the 5294 control units and a data link cable remote data processing.
When the era of personal computers began connecting cards have been offered for this, which provided the so-called 5250 emulation. This could work as a PC terminal on the System/36
For faster data backup were offered from 1985 magnetic tape cartridges and equipment, ranging from capacities of a few dozen to a few hundred Mbytes.
Operating system and programming
The operating system SSP had a general menu control, the / 36 made much more user-friendly compared to / 38. So you could select commands from a menu structure and select parameters via function keys, which is not so savvy administrators facilitated complicated functions. Was programmed on the System/36 OCL (Operating Control Language ) as a control language and BASIC, COBOL or RPG programming language. For this purpose, the tools SEU ( Source Entry Utility) and SDA ( Screen Design Aid) were available. Furthermore, a as POP ( Programmer and Operator Productivity Aid) designated offered help, which made it possible to call all functions via menus.
In practice, it was often necessary to perform a Compress, similar to today Defragment in Windows PCs. This vacant areas of the disk were grouped into larger blocks, so that the operating system could have this place again, since new data to be written could be written only into suitable blocks. This often lasted several hours.
Detachment
The high maintenance fees and the limited extensibility of the S/36 then led to the development of the successor model AS/400 in 1988. System/36 But that was still a few years in predominantly medium-sized businesses further, has even survived the turn of the millennium still in operation.