RC 4000 multiprogramming system - Revision history

Blainster: /* Overview */ copyedit section, concise; rmv superfluous "notable/notably", which is required in Wikipedia; write directly

2025-06-23T09:34:25Z

Overview: copyedit section, concise; rmv superfluous "notable/notably", which is required in Wikipedia; write directly

← Previous revision		Revision as of 09:34, 23 June 2025
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	==Overview==		==Overview==
	The RC 4000 Multiprogramming System ~~is historically notable for being~~ the first attempt to break down an operating system into a group of interacting programs communicating via a [[message passing]] [[Kernel (operating system)\|kernel]]. RC 4000 was not widely used, but was highly influential, sparking the [[microkernel]] concept that dominated operating system research through the 1970s and 1980s.		The RC 4000 Multiprogramming System was the first attempt to break down an operating system into a group of interacting programs communicating via a [[message passing]] [[Kernel (operating system)\|kernel]]. RC 4000 was not widely used, but was highly influential, sparking the [[microkernel]] concept that dominated operating system research through the 1970s and 1980s.

	Monitor was created largely by one programmer, [[Per Brinch Hansen]], who worked at [[Regnecentralen]] where the RC 4000 was being designed. Leif Svalgaard participated in implementing and testing Monitor. Brinch Hansen found that no existing operating system was suited to the new machine, and was tired of having to adapt existing systems. He felt that a better solution was to build an underlying kernel, which he referred to as the ''nucleus'', that could be used to build up an operating system from interacting programs. [[Unix]], for instance, uses small interacting programs for many tasks, transferring data through a system called ''[[Pipeline (Unix)\|pipelines or pipes]]''. However, a large amount of fundamental code is integrated into the kernel, ~~notably~~ things like [[file system]]s and program control. Monitor would relocate such code also, making almost the entire system a set of interacting programs, reducing the kernel (nucleus) to a communications and support system only.		Monitor was created largely by one programmer, [[Per Brinch Hansen]], who worked at [[Regnecentralen]] where the RC 4000 was being designed. Leif Svalgaard participated in implementing and testing Monitor. Brinch Hansen found that no existing operating system was suited to the new machine, and was tired of having to adapt existing systems. He felt that a better solution was to build an underlying kernel, which he referred to as the ''nucleus'', that could be used to build up an operating system from interacting programs. [[Unix]], for instance, uses small interacting programs for many tasks, transferring data through a system called ''[[Pipeline (Unix)\|pipelines or pipes]]''. However, a large amount of fundamental code is integrated into the kernel, things like [[file system]]s and program control. Monitor would relocate such code also, making almost the entire system a set of interacting programs, reducing the kernel (nucleus) to a communications and support system only.

	Monitor used a pipe-like system of shared memory as the basis of its [[inter-process communication]] (IPC). Data to be sent from one process to another was copied into an empty memory [[data buffer]], and when the receiving program was ready, back out again. The buffer was then returned to the pool. Programs had a very simple application programming interface ([[API]]) for passing data, using an [[wikt:asynchronous\|asynchronous]] set of four methods. Client applications send data with <code>send message</code> and could optionally block using <code>wait answer</code>. Servers used a mirroring set of calls, <code>wait message</code> and <code>send answer</code>. Note that messages had an implicit "return path" for every message sent, making the semantics more like a [[remote procedure call]] than [[Mach (kernel)\|Mach's]] completely [[input/output]] (I/O) based system.		Monitor used a pipe-like system of shared memory as the basis of its [[inter-process communication]] (IPC). Data to be sent from one process to another was copied into an empty memory [[data buffer]], and when the receiving program was ready, back out again. The buffer was then returned to the pool. Programs had a very simple application programming interface ([[API]]) for passing data, using an [[wikt:asynchronous\|asynchronous]] set of four methods. Client applications send data with <code>send message</code> and could optionally block using <code>wait answer</code>. Servers used a mirroring set of calls, <code>wait message</code> and <code>send answer</code>. Note that messages had an implicit "return path" for every message sent, making the semantics more like a [[remote procedure call]] than [[Mach (kernel)\|Mach's]] completely [[input/output]] (I/O) based system.

87.62.89.153: This system is significantly larger than any other machine usually refered to as a mini-computer. https://datamuseum.dk/wiki/RC4000

2025-03-08T17:26:37Z

This system is significantly larger than any other machine usually refered to as a mini-computer. https://datamuseum.dk/wiki/RC4000

← Previous revision		Revision as of 17:26, 8 March 2025
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	The '''RC 4000 Multiprogramming System''' (also termed '''Monitor''' or '''RC 4000''' depending on reference) is a discontinued [[operating system]] developed for the RC-4000 ~~[[minicomputer]]~~ in 1969.<ref>{{Cite web \|title=Nuclear · Lecture Note for 221 \|url=https://yutingwang.gitbooks.io/lecture-note-for-221/content/nuclear1.html \|access-date=2024-04-10 \|website=yutingwang.gitbooks.io}}</ref> For clarity, this article mostly uses the term Monitor.		The '''RC 4000 Multiprogramming System''' (also termed '''Monitor''' or '''RC 4000''' depending on reference) is a discontinued [[operating system]] developed for the RC-4000 third generation computer in 1969.<ref>{{Cite web \|title=Nuclear · Lecture Note for 221 \|url=https://yutingwang.gitbooks.io/lecture-note-for-221/content/nuclear1.html \|access-date=2024-04-10 \|website=yutingwang.gitbooks.io}}</ref> For clarity, this article mostly uses the term Monitor.

	==Overview==		==Overview==

Procyon117: v2.05 - Fix errors for CW project (Reference list missing)

2024-04-11T16:47:39Z

v2.05 - Fix errors for CW project (Reference list missing)

← Previous revision		Revision as of 16:47, 11 April 2024
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	==References==		==References==
			{{reflist}}
	*{{cite journal \|last=Hansen \|first=Per Brinch \|year=1970 \|title=The Nucleus of a Multiprogramming Operating System \|url=http://www.brinch-hansen.net/papers/1970a.pdf \|journal=Communications of the ACM \|volume=13 \|issue=4 \|pages=238–250 \|publisher=[[Association for Computing Machinery]] \|doi=10.1145/362258.362278 \|citeseerx=10.1.1.105.4204\|s2cid=9414037 }}		*{{cite journal \|last=Hansen \|first=Per Brinch \|year=1970 \|title=The Nucleus of a Multiprogramming Operating System \|url=http://www.brinch-hansen.net/papers/1970a.pdf \|journal=Communications of the ACM \|volume=13 \|issue=4 \|pages=238–250 \|publisher=[[Association for Computing Machinery]] \|doi=10.1145/362258.362278 \|citeseerx=10.1.1.105.4204\|s2cid=9414037 }}
	*[http://brinch-hansen.net/papers/1969a.pdf RC 4000 Software: Multiprogramming System]		*[http://brinch-hansen.net/papers/1969a.pdf RC 4000 Software: Multiprogramming System]

Elilopes at 20:31, 10 April 2024

2024-04-10T20:31:00Z

← Previous revision		Revision as of 20:31, 10 April 2024
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	}}		}}
	The '''RC 4000 Multiprogramming System''' (also termed '''Monitor''' or '''RC 4000''' depending on reference) is a discontinued [[operating system]] developed for the RC~~ ~~4000 [[minicomputer]] in 1969. For clarity, this article mostly uses the term Monitor.		The '''RC 4000 Multiprogramming System''' (also termed '''Monitor''' or '''RC 4000''' depending on reference) is a discontinued [[operating system]] developed for the RC-4000 [[minicomputer]] in 1969.<ref>{{Cite web \|title=Nuclear · Lecture Note for 221 \|url=https://yutingwang.gitbooks.io/lecture-note-for-221/content/nuclear1.html \|access-date=2024-04-10 \|website=yutingwang.gitbooks.io}}</ref> For clarity, this article mostly uses the term Monitor.

	==Overview==		==Overview==

The Little Wiki Student: #suggestededit-add 1.0

2023-07-16T08:56:24Z

#suggestededit-add 1.0

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			{{Short description\|Technological System (Discontinued)}}
	{{No footnotes\|date=January 2019}}		{{No footnotes\|date=January 2019}}
	{{Use dmy dates\|date=September 2021}}		{{Use dmy dates\|date=September 2021}}

Citation bot: Add: s2cid. | Use this bot. Report bugs. | Suggested by Whoop whoop pull up | #UCB_webform 927/3352

2023-03-27T06:39:52Z

Add: s2cid. | Use this bot. Report bugs. | Suggested by Whoop whoop pull up | #UCB_webform 927/3352

← Previous revision		Revision as of 06:39, 27 March 2023
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	==References==		==References==
	*{{cite journal \|last=Hansen \|first=Per Brinch \|year=1970 \|title=The Nucleus of a Multiprogramming Operating System \|url=http://www.brinch-hansen.net/papers/1970a.pdf \|journal=Communications of the ACM \|volume=13 \|issue=4 \|pages=238–250 \|publisher=[[Association for Computing Machinery]] \|doi=10.1145/362258.362278 \|citeseerx=10.1.1.105.4204}}		*{{cite journal \|last=Hansen \|first=Per Brinch \|year=1970 \|title=The Nucleus of a Multiprogramming Operating System \|url=http://www.brinch-hansen.net/papers/1970a.pdf \|journal=Communications of the ACM \|volume=13 \|issue=4 \|pages=238–250 \|publisher=[[Association for Computing Machinery]] \|doi=10.1145/362258.362278 \|citeseerx=10.1.1.105.4204\|s2cid=9414037 }}
	*[http://brinch-hansen.net/papers/1969a.pdf RC 4000 Software: Multiprogramming System]		*[http://brinch-hansen.net/papers/1969a.pdf RC 4000 Software: Multiprogramming System]
	*[http://bitsavers.org/pdf/regnecentralen/RC_4000_Reference_Manual_Jun69.pdf RC 4000 Reference Manual] at bitsavers.org		*[http://bitsavers.org/pdf/regnecentralen/RC_4000_Reference_Manual_Jun69.pdf RC 4000 Reference Manual] at bitsavers.org

Jerryobject: MOS:DATETIES Template:Use dmy dates. Template:Infobox OS, WP:REFerence WP:CITations > parameters: updates, reorders, adds, fills, author > last + first. WP:LEADSENTENCE MOS:BOLDSYNonyms moved after title term 1st instance. Small WP:EoS WP:TERSE WP:COPYEDITs; WP:IDIOM > WP:FORMAL. WP:LINKs: adds, updates, fix needless WP:PIPEs (WP:NOPIPEs). MOS:FIRSTABBReviations define before WP:ABBRs in parentheses. WP:NAVBOX update.

2021-09-08T10:23:47Z

MOS:DATETIES Template:Use dmy dates. Template:Infobox OS, WP:REFerence WP:CITations > parameters: updates, reorders, adds, fills, author > last + first. WP:LEADSENTENCE MOS:BOLDSYNonyms moved after title term 1st instance. Small WP:EoS WP:TERSE WP:COPYEDITs; WP:IDIOM > WP:FORMAL. WP:LINKs: adds, updates, fix needless WP:PIPEs (WP:NOPIPEs). MOS:FIRSTABBReviations define before WP:ABBRs in parentheses. WP:NAVBOX update.

Show changes

Ghettoblaster at 15:07, 9 February 2020

2020-02-09T15:07:50Z

← Previous revision		Revision as of 15:07, 9 February 2020
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	*[http://bitsavers.org/pdf/regnecentralen/RC_4000_Reference_Manual_Jun69.pdf RC 4000 Reference Manual] at bitsavers.org		*[http://bitsavers.org/pdf/regnecentralen/RC_4000_Reference_Manual_Jun69.pdf RC 4000 Reference Manual] at bitsavers.org

		⚫	{{MicroKernel}}
⚫	<!--[[Category:Operating systems]] delete. Mickrokernels is a subcat of this -->

		⚫	<!--[[Category:Operating systems]] delete. Mickrokernels is a subcat of this -->
	[[Category:Microkernel-based operating systems]]		[[Category:Microkernel-based operating systems]]
	[[Category:Microkernels]]		[[Category:Microkernels]]
			[[Category:1969 software]]
⚫	{{MicroKernel}}

Jerryobject: /* References */ Nonacronym nonproper noun WP:ALLCAPS > title case.

2019-12-24T13:17:54Z

References: Nonacronym nonproper noun WP:ALLCAPS > title case.

← Previous revision		Revision as of 13:17, 24 December 2019
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	==References==		==References==
	*{{cite journal \| author = Brinch Hansen, Per \| year = 1970 \| volume = 13 \| title = The Nucleus of a Multiprogramming Operating System \| journal = Communications of the ACM \| pages = 238–250 \| url = http://www.brinch-hansen.net/papers/1970a.pdf \| doi = 10.1145/362258.362278 \| issue = 4\| citeseerx = 10.1.1.105.4204 }}		*{{cite journal \|author=Brinch Hansen, Per \|year=1970 \|volume=13 \|title=The Nucleus of a Multiprogramming Operating System \|journal=Communications of the ACM \|pages=238–250 \|url=http://www.brinch-hansen.net/papers/1970a.pdf \|doi=10.1145/362258.362278 \|issue=4 \|citeseerx=10.1.1.105.4204}}
	*[http://brinch-hansen.net/papers/1969a.pdf RC 4000 ~~SOFTWARE~~: ~~MULTIPROGRAMMING~~ ~~SYSTEM~~]		*[http://brinch-hansen.net/papers/1969a.pdf RC 4000 Software: Multiprogramming System]
	*[http://bitsavers.org/pdf/regnecentralen/RC_4000_Reference_Manual_Jun69.pdf RC 4000 Reference Manual] at bitsavers.org		*[http://bitsavers.org/pdf/regnecentralen/RC_4000_Reference_Manual_Jun69.pdf RC 4000 Reference Manual] at bitsavers.org

	<!--[[Category:Operating systems]] delete. Mickrokernels is a subcat of this -->		<!--[[Category:Operating systems]] delete. Mickrokernels is a subcat of this -->

	[[Category:Microkernel-based operating systems]]		[[Category:Microkernel-based operating systems]]

125.234.115.122: /* Overview */Unreferenced opinion

2019-07-12T14:57:45Z

Overview: Unreferenced opinion

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	[[Scheduling (computing)\|Scheduling]] was left entirely to the programs, if required at all (in the 1960s, [[computer multitasking\|multitasking]] was a debatable feature). One user could start up a session in a [[pre-emptive multitasking]] environment, while another might start in a single-user mode to run [[batch processing]] at higher speed. [[Real-time computing\|Real-time]] scheduling could be supported by sending messages to a timer process that would only return at the appropriate time.		[[Scheduling (computing)\|Scheduling]] was left entirely to the programs, if required at all (in the 1960s, [[computer multitasking\|multitasking]] was a debatable feature). One user could start up a session in a [[pre-emptive multitasking]] environment, while another might start in a single-user mode to run [[batch processing]] at higher speed. [[Real-time computing\|Real-time]] scheduling could be supported by sending messages to a timer process that would only return at the appropriate time.

	Monitor proved to have truly terrible performance. Much of this was due to the cost of IPC, a problem that has since plagued most microkernels. Under Monitor data was copied twice for every message, and memory handling on the RC 4000 was not particularly fast. Another area of serious concern was launching and killing programs to handle requests, which happened all the time.

	These two areas have seen the vast majority of development since Monitor's release, driving newer designs to use hardware to support messaging, and supporting threads within applications to reduce launch times. For instance, Mach required a [[memory management unit]] to improve messaging by using the [[copy-on-write]] protocol and mapping (instead of copying) data from process to process. Mach also used threading extensively, allowing the external programs, or ''servers'' in more modern terms, to easily start up new handlers for incoming requests. Still, Mach IPC was too slow to make the microkernel approach practically useful. This only changed when Liedtke [[L4 microkernel family\|L4 microkernel]] demonstrated an order-of-magnitude improvement in IPC overheads.		These two areas have seen the vast majority of development since Monitor's release, driving newer designs to use hardware to support messaging, and supporting threads within applications to reduce launch times. For instance, Mach required a [[memory management unit]] to improve messaging by using the [[copy-on-write]] protocol and mapping (instead of copying) data from process to process. Mach also used threading extensively, allowing the external programs, or ''servers'' in more modern terms, to easily start up new handlers for incoming requests. Still, Mach IPC was too slow to make the microkernel approach practically useful. This only changed when Liedtke [[L4 microkernel family\|L4 microkernel]] demonstrated an order-of-magnitude improvement in IPC overheads.

← Previous revision		Revision as of 08:56, 16 July 2023
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			{{Short description\|Technological System (Discontinued)}}
	{{No footnotes\|date=January 2019}}		{{No footnotes\|date=January 2019}}
	{{Use dmy dates\|date=September 2021}}		{{Use dmy dates\|date=September 2021}}