System / 34
The System / 34 (also S / 34 ) was a minicomputer architecture from IBM . It was presented in April 1977 as an inexpensive alternative to the mainframe computers of the S / 370 series. It was the successor of the System / 32 and the forerunner of the System / 36 as well as the smaller sister system of the S / 38 . The S / 34 served as a multi-user computer for departments and smaller companies and was produced until February 1985 .
hardware
The main memory capacity was a maximum of 256 kilobytes of RAM . The S / 34 could be operated in the basic configuration with two and with an extension module with four disk drives with 64 megabytes each . A connected and operational chain printer was required as a system printer for operation . Its absence did not make the operation of the S / 34 impossible, but when the system was started it was acknowledged with an error message requiring an answer. The data was backed up exclusively using 8 ″ floppy disks . Depending on the version of the S / 34, there were three individual feeds or two additional slots for magazines with ten diskettes each.
A maximum of 14 terminals of type 5250 could be connected to the system with twinaxial cables . Up to 7 devices could be connected to one line and connected in series. Each terminal had an entrance and exit. The end device had to be terminated. The terminal on the first line in the first position with the logical address 0/0 was the control or system console for operators and administrators, on which the error messages of the SSP operating system, the so-called System Reference Codes (SRC), could be read and answered if necessary . All other control of the S / 34 including the monitoring of the system start ( Initial Program Loading , IPL ) and the reorganization of the disks ( Compress ) took place here.
Operating system and programming
The system was divided into four parts:
- the basic SSP operating system in a protected area that is only accessible to IBM technicians with special diskettes;
- the system programs of the SSP stored in libraries and optional additional routines such as compilers, program generators, etc .;
- the application programs stored in libraries (source code and machine programs);
- the sequential, direct, or simply indexed data files.
The proprietary operating system SSP appeared in nine versions. It had a general menu control that made the S / 34 much more user-friendly despite the significantly fewer functions compared to the S / 38 . So you could select commands from a menu structure, which made complicated functions easier for not so experienced administrators and especially for users. The System / 34 was programmed using OCL (Operating Control Language) as the control language and RPG or, more rarely, Cobol as the programming language.
The tools SEU (Source Entry Utility) were available as a single line editor for the source code and SDA (Screen Design Aid) as a design tool for screen masks. In addition, a help called POP (Programmer and Operator Productivity Aid) was offered, which included a full screen editor (FSE). It made it possible to call up many of the functions necessary for system developers via special menus and control programs. In addition, generators were available which enabled simple dialog processing or the quick printout of data files.
In practice, it was often necessary to carry out a compress to reorganize the disks , 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.
literature
- Charlie Massoglia: Everything You Always Wanted to Know About the System / 34 But Nobody Told You .
- Charlie Massoglia: Writing and Using System / 34 Procedures Effectively .
- Charlie Massoglia: System / 3 and System / 34 Disk Sort as a Programming Language .
Web links
Individual evidence
- ^ IBM Corporation: System / 34 . In: IBM Archives . Retrieved December 4, 2012.