System / 38
System / 38 is a mini computer from IBM . The system was announced in 1978 and first shipped in August 1979. The System / 38 (also S38, System38) was developed by Frank Soltis in the IBM laboratory in Rochester . It is designed as a multi-user and multi-threaded system for commercial applications.
It was intended to be the successor to the IBM System / 3 and had an advanced object-based architecture. According to a market analysis in 1983, 69 percent of customers previously used the IBM System / 3. The goal of getting this group of customers to switch to the new computer was achieved. The system / 38 was replaced in 1988 by the successor system AS / 400 , which today operates under the name System i .
Operating system and database
The system / 38 was designed with a relational database for dialog processing . The system also performed well with batch processing such as B. daily closings, inventories u. Ä.
The operating system, called the system control program CPF , was tailored precisely to this machine and hardware. The operation could take place via the control language program CL . Originally only two programming languages were supplied. That was COBOL and RPG III . Later came PL / 1 and BASIC added as a programming language. The relational database was integrated into the operating system.
Hardware independence
The goal was to build a computer where the programmers were independent of the hardware. This should mean that the hardware and its interface to the applications could be exchanged without the programs having to be recompiled. That was by no means taken for granted back then. A multi-level layer model was developed for this.
- hardware
- Horizontal microcode
- Vertical microcode
- High-level architecture interface
- Languages, database, tools, CPF ( Control Program Facility )
- Applications
Memory and memory addressing
The system / 38 had a working memory of 512K, 768K or 1024K (Model 3XX and 5XX) or 1280K or 1536K (Model 5XX). The computer was able to address a 48-bit address space and was able to dispose of all memories (disks and RAM ) in one address space.
User administration and authorizations
The system was multi-user capable and thus also had user administration. An object authorization architecture made it possible to assign rights at the object level. This made it possible to set up an authorization system that stipulated exactly in which way a program, file or other object could be used by a user.
Input / output devices
Twinax terminals were used as display devices. By default, 12 and a maximum of 40 IBM 5250s were used. Twinax was only used by the IBM. The twinax system allows seven devices connected in series on one line. There were twinax screens and twinax printers. Furthermore, data could also be read via 8-inch floppy disks. For example, the operating system was delivered on several floppy disks . The system was also backed up on floppy disks. Disk magazines were usually used for this purpose. Each of these magazines could hold 10 disks.
literature
- Henry M. Levy: The IBM System / 38 . In: Capability-Based Computer Systems . Digital Press, 1984, ISBN 0-932376-22-3 .
- [1978] IBM System / 38 Technical Developments . IBM Product Design and Development, General Systems Division, 1980, ISBN 0-933186-03-7 , G580-0237-1.
Web links
- Black box also for advanced users (article in Computerwoche 45/1978 of November 3, 1978)
- Archives of IBM for 1978 (English)
- IBM Glossary (English)
Individual evidence
- ↑ http://www.computerwoche.de/heftarchiv/1983/10/1177867/ ( page no longer available , search in web archives ) Info: The link was automatically marked as defective. Please check the link according to the instructions and then remove this notice. Article of Computerwoche (1983)
