Английская Википедия:Interactive Application System
Шаблон:Short description Шаблон:Use mdy dates Шаблон:Use American English Шаблон:Infobox OS Interactive Application System (IAS) was a DEC operating system for the PDP-11.[1] It was a fork from RSX-11D.[2][3]
The last major release, Version 3.0, began distribution late 1979;[4] the final version, 3.4, came out May 1990.[1]
Overview
DEC's RSX-11A and C were paper tape based, B had limited disk support, "D" was for disk, and the "M" designation was for "small Memory requirement" /later "Multi-user"[3] (with RSX-11M Plus being a followup). IAS was designed to a mix of "concurrent timesharing, real-time and batch."[5][6] A looking back described it as "bare basics .. handled interrupts .. scheduled processes, and provided interprocess communications" without being "all things to all people."[7] Another description, rather than focusing on taking away overhead, wrote "IAS (Interactive Application System) was created by adding two things to 11D."[8]
RSX-11's use of a version number as part of a file's identifier: MYFILE.DAT;3[9] was retained by IAS. [1]Шаблон:Rp
The batch facility's command files used the same syntax as the indirect command files available to interactive users; multiple batch jobs could run concurrently.[1]Шаблон:Rp The system could be tuned to either leave unused CPU cycles to batch, or to guarantee a minimum level (without taking from Real Time requirements).[1]Шаблон:Rp[10]Шаблон:Rp[11]
DEC's Sort/Merge utility program was distributed as part of IAS.[1]Шаблон:Rp
Performance
The system can be operated in one of three modes: Real-Time, Multi-User, and Timesharing.[10]
Multi-User shares the system with Real-Time tasks; Timesharing adds effective concurrent use of batch processing alongside "noncritical real-time tasks" and interactive users.[10]Шаблон:Rp Timesharing also adds Timesharing Control Primitives (TCP), described as a "mechanism for timesharing tasks to invoke and communicate with other timesharing tasks."[10]Шаблон:Rp An evaluation by TRW's Defense and Space Systems Group for Tactical Operations Analysis Support Facility at Langley AFB VA highlighted the "IAS heuristic timesharing scheduler" and "subtasking support at the Kernel Executive level via the SPAWN system directive."[10]Шаблон:Rp
The heuristic timesharing scheduler tracks "history of performance and degree of interaction."[10]Шаблон:Rp
Some failure recovery is built into both the DEC hardware and IAS software.[12]
References
Шаблон:Digital Equipment Corporation
- ↑ 1,0 1,1 1,2 1,3 1,4 1,5 Шаблон:Cite web
- ↑ "D" for Disk, since 11A & 11C were paper-tape based
- ↑ 3,0 3,1 Шаблон:Cite web
- ↑ Шаблон:Cite web
- ↑ Шаблон:Cite news
- ↑ Шаблон:Cite news
- ↑ Шаблон:Cite web
- ↑ Шаблон:Cite web
- ↑ Шаблон:Cite web
- ↑ 10,0 10,1 10,2 10,3 10,4 10,5 Шаблон:Cite book
- ↑ "Inter-task transmission .. region access"
- ↑ Шаблон:Cite report
