Английская Википедия:IBM System/34
Шаблон:Short description Шаблон:More citations needed Шаблон:Infobox Computer The IBM System/34 was an IBM midrange computer introduced in 1977.[1] It was withdrawn from marketing in February 1985.[1] It was a multi-user, multi-tasking successor to the single-user System/32. It included two processors, one based on the System/32 and the second based on the System/3. Like the System/32 and the System/3, the System/34 was primarily programmed in the RPG II language.[2]
Hardware
The 5340 System Unit contained the processing unit, the disk storage and the diskette drive. It had several access doors on both sides. Inside, were swing-out assemblies where the circuit boards and memory cards were mounted. It weighed Шаблон:Cvt and used 220V power.[3] The IBM 5250 series of terminals were the primary interface to the System/34.
Processors
S/34s had two processors, the Control Storage Processor (CSP), and the Main Storage Processor (MSP). The MSP was the workhorse, based on System/3 architecture; it performed the instructions in the computer programs. The CSP was the governor, a different processor with different RISC-like instruction set, based on System/32 architecture; it performed system functions in the background. The CSP also executed the optional Scientific Macroinstructions, which were a set of emulated floating point operations used by the System/34 Fortran compiler and optionally in assembly code.[4] The clock speed of the CPUs inside a System/34 was fixed at 1 MHz for the MSP and 4 MHz for the CSP. Special utility programs were able to make direct calls to the CSP to perform certain functions; these are usually system programs like $CNFIG which was used to configure the computer system.
Memory and storage
The smallest S/34 had 48K of RAM and an 8.6 MB hard drive. The largest configured S/34 could support 256K of RAM and 256MB of disk space. S/34 hard drives contained a feature called "the extra cylinder," so that bad spots on the drive were detected and dynamically mapped out to good spots on the extra cylinder. Disk space on the System/34 was organized by blocks of 2560 bytes.
The System/34 supported memory paging, referring to as swapping.[5] The System/34 could either swap out entire programs, or individual segments of a program in order to free up memory for other programs to run.
One of the machine's most distinctive features was an off-line storage mechanism that utilized "Шаблон:Visible anchor" - boxes of 8-inch floppies that the machine could load and eject in a nonsequential fashion.[6][7][8]
Software
Operating System
The System Support Program (SSP) was the only operating system of the S/34. It contained support for multiprogramming, multiple processors, 36 devices, job queues, printer queues, security, indexed file support. Fully installed, it was about 5 MB.[9] The Operational Control Language (OCL) was the control language of SSP.
Programming
The System/34's initial programming languages were limited to RPG II and Basic Assembler[10] when introduced in 1977.[11] FORTRAN was fully available six months after the 34's introduction,[6] and COBOL was available as a PRPQ.[12] BASIC was introduced later.
Successor systems
The IBM System/38 was intended to be the successor of the System/34 and the earlier System/3x systems. However, due to the delays in the development of the System/38 and the high cost of the hardware once complete, IBM developed the simpler and cheaper System/36 platform which was more widely adopted than the System/38.[13] The System/36 was an evolution of the System/34 design, but the two machines were not object-code compatible. Instead, the System/36 offered source code compatibility, allowing System/34 applications to be recompiled on a System/36 with little to no changes. Some System/34 hardware was incompatible with the System/36.
A third party product from California Software Products, Inc. named BABY/34 allowed System/34 applications to be ported to IBM PC compatible hardware running MS-DOS. [14] [15]
References
Further reading
External links
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Шаблон:IBM midrange computers Шаблон:Authority control
- ↑ 1,0 1,1 Шаблон:Cite web
- ↑ Шаблон:Cite web
- ↑ Шаблон:Cite news
- ↑ Шаблон:Cite web
- ↑ Шаблон:Cite web
- ↑ 6,0 6,1 Шаблон:Cite book
- ↑ "the diskette magazine drive can process up to 23 diskettes without manual intervention. -p.11
- ↑ "three slots for holding individual diskettes and two slots for holding magazines of 10 individual diskettes." -p.20
- ↑ Шаблон:Cite web
- ↑ Шаблон:Cite news
- ↑ Шаблон:Cite news
- ↑ "potentially available ... special order"
- ↑ Шаблон:Cite book
- ↑ Шаблон:Cite magazine
- ↑ Шаблон:Cite magazine
