Introduction - Revision history

PumpkinPieman: Small formatting edit, no real large corrections.

2007-10-21T21:10:44Z

Small formatting edit, no real large corrections.

← Older revision		Revision as of 21:10, 21 October 2007
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	What are some properties of the machine that we want?		What are some properties of the machine that we want?

	- usable / accessible		<dl>
	- stable / reliable		<ul>- usable / accessible</ul>
	- functional (access to underlying resources)		<ul>- stable / reliable</ul>
	- efficient		<ul>- functional (access to underlying resources)</ul>
	- customizable		<ul>- efficient</ul>
	- secure		<ul>- customizable</ul>
	- multitasking		<ul>- secure</ul>
	- ~~portability~~		<ul>- multitasking</ul>
			<ul>- portable</ul>
			</dl>

	If you have a computer that doesn't let you access the hardware, eg. a		Examples:
	~~keyboard or video camera~~, it isn't very functional. ~~Multitasking is slightly different than efficiency.~~		<dl>
	For portability, do you really want to have to rewrite applications to support		<ul>- If you have a computer that doesn't let you access the hardware via an input device (eg: keyboard, mouse, etc..), it isn't very functional.</ul>
			<ul>- For portability, do you really want to have to rewrite applications to support
	slight variations in the hardware such as different size hard disks and different		slight variations in the hardware such as different size hard disks and different
	amounts of RAM?		amounts of RAM?</ul>
			<ul>- Multitasking is slightly different than efficiency. (''needs editing and expanding, very unclear'')</ul>
			</dl>


	Operating systems don't do all of these perfectly, but they tend to do a lot		Operating systems don't do all of these perfectly, but they tend to do a lot
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	If you look at the introduction to the text book, it talks about various		If you look at the introduction to the text book, it talks about various
	types of ~~operatings~~ systems. Some of the operating systems we know about are:		types of operating systems. Some of the operating systems we know about are:
	Linux, Windows, MacOSX, VXWorks, QNX, MS-DOS, Soliaris/xBSD, OS/2, BeOS, VMS,		Linux, Windows, MacOSX, VXWorks, QNX, MS-DOS, Soliaris/xBSD, OS/2, BeOS, VMS,
	MVS, OS/370, AIX, etc.		MVS, OS/370, AIX, etc.

	Linux isn't a variety of different operating systems to the same degree as the		Linux isn't a variety of different operating systems to the same degree as the
	different versions of windows, as most ~~linuxes~~ share some components, ~~whereas~~ windows tends not to.		different versions of windows, as most linuxs' share some components, where as windows tends not to.

	Of the list above, most of them are modern operating systems~~, except MS-DOS~~.		Of the list above, most of them are modern operating systems.
	To be a "modern" OS, there are two major qualities: Does it have protected		To be a "modern" OS, there are two major qualities: Does it have protected
	memory, and does it have pre-emptive multitasking?		memory, and does it have pre-emptive multitasking? (MS-DOS wouldn't apply to this list because it doesn't constitute as a modern OS.)

	=== Protected Memory ===		=== Protected Memory ===
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	=== Preemptive Multi-tasking ===		=== Preemptive Multi-tasking ===

	A way to have more than one program run at a time. Older machines were known		Preemptive Multitasking is a way to have more than one program run at a time. Older machines were known
	as batch machines and their operating systems were batch operating systems.		as batch machines and their operating systems were batch operating systems. These machines ran tasks that took a long time to finish execution, so the tasks were placed in a queue and run one at a time in sequence. These were typically things such things as payroll and accounts receivable for large business. Usually these would be left to run overnight and output the result of the tasks either on magnetic tape or a
	These ran tasks that took a long time to ~~run. These~~ were ~~queued up,~~ and run		stack of printouts, which would be returned to the user in the morning.
	one at a time in sequence. These were typically things such things as payroll and accounts receivable.
	Usually these would be run overnight and the ~~output,~~ either on magnetic tape or a
	stack of printouts which would be returned to the user in the morning.

	~~Preemptive multitasking - the OS enforces time sharing.~~
	~~Co-operative multitasking - each program lets others run~~.

	~~If you look at MS~~-~~DOS, there are batch files~~. ~~These are just a sequence of~~		What is the difference between preemptive multitasking and cooperative multitasking?
	~~commands to~~ run. ~~It runs them and then returns when done.~~		<dl>
			<ul>- Preemptive multitasking: the OS enforces time sharing.</ul>
			<ul>- Co-operative multitasking: each program lets others run.</ul>
			</dl>

	If you want to run a GUI, however, a batch system is unlikely to be what you want, as		Examples:
	a GUI environment tends to be interactive.		<dl>
			<ul>If you look at MS-DOS, there are batch files. These are just a sequence of
			commands to run. It runs them and then returns when done. (cooperative)</ul>
			<ul>If you want to run a GUI, however, a batch system is unlikely to be what you want, as
			a GUI environment tends to be interactive. (preemptive)</ul>
			</dl>

	With the big iron in the old days they had big computers that would be sitting		With the big iron in the old days they had big computers that would be sitting

Rhooper at 01:21, 18 September 2007

2007-09-18T01:21:33Z

← Older revision		Revision as of 01:21, 18 September 2007
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	These notes ~~are~~ have not yet been reviewed for correctness.		These notes have not yet been reviewed for correctness.

	== Introduction ==		== Introduction ==

Rhooper at 00:45, 18 September 2007

2007-09-18T00:45:57Z

← Older revision		Revision as of 00:45, 18 September 2007
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			These notes are have not yet been reviewed for correctness.

	== Introduction ==		== Introduction ==

Rhooper at 18:14, 16 September 2007

2007-09-16T18:14:49Z

← Older revision		Revision as of 18:14, 16 September 2007
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	a buffer so its not overwritten when the next key is pressed, then returns.		a buffer so its not overwritten when the next key is pressed, then returns.

			{\|align="right"
			\|[[Image:Stored_program_architecture_2.png]]
			\|}
	Think of an interrupt as a little kid pulling at your pant leg. It wants your attention now.		Think of an interrupt as a little kid pulling at your pant leg. It wants your attention now.

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	then keep running and perform its tasks as it needs:		then keep running and perform its tasks as it needs:
	"Is everyone behaving nicely? Do I need to kill anyone?"		"Is everyone behaving nicely? Do I need to kill anyone?"

	~~[[Image:Stored_program_architecture_2.png]]~~

	=== Virtual Memory ===		=== Virtual Memory ===
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	This has to do with the nature of the processes:		This has to do with the nature of the processes:

	[[Image:Processes_and_kernel.png]]		{\|align="right"
			\|[[Image:Processes_and_kernel.png]]
			\|}
	To upgrade things, the kernel trusts some programs/users to allow them to		To upgrade things, the kernel trusts some programs/users to allow them to
	upgrade. In windows, you tend to run as the user admin. This means you're		upgrade. In windows, you tend to run as the user admin. This means you're

Rhooper at 18:13, 16 September 2007

2007-09-16T18:13:48Z

← Older revision		Revision as of 18:13, 16 September 2007
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	This has to do with the nature of the processes:		This has to do with the nature of the processes:

	[[Image:Processes_and_kernel.~~png‎~~]]		[[Image:Processes_and_kernel.png]]

	To upgrade things, the kernel trusts some programs/users to allow them to		To upgrade things, the kernel trusts some programs/users to allow them to

Rhooper at 18:09, 16 September 2007

2007-09-16T18:09:57Z

← Older revision		Revision as of 18:09, 16 September 2007
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	== Introduction == ~~(continued)~~		== Introduction ==

	[[Class Outline#Introduction\|Last class]], we began talking about turning the machine we have into the machine we want.		[[Class Outline#Introduction\|Last class]], we began talking about turning the machine we have into the machine we want.

Rhooper at 18:09, 16 September 2007

2007-09-16T18:09:48Z

← Older revision		Revision as of 18:09, 16 September 2007
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	== Introduction ==		== Introduction == (continued)

	[[Class Outline#Introduction\|Last class]], we began talking about turning the machine we have into the machine we want.		[[Class Outline#Introduction\|Last class]], we began talking about turning the machine we have into the machine we want.

Rhooper at 18:09, 16 September 2007

2007-09-16T18:09:28Z

← Older revision		Revision as of 18:09, 16 September 2007
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	== Introduction ==		== Introduction ==

	Last class, we began talking about turning the machine we have into the machine we want.		[[Class Outline#Introduction\|Last class]], we began talking about turning the machine we have into the machine we want.

	What are some properties of the machine that we want?		What are some properties of the machine that we want?

Rhooper at 18:07, 16 September 2007

2007-09-16T18:07:27Z

@@ Line 1: / Line 1: @@
 == Introduction ==
@@ Line 216: / Line 215: @@
 There's one small problem with Vista and XP, however.
 This has to do with the nature of the processes:
 To upgrade things, the kernel trusts some programs/users to allow them to
@@ Line 245: / Line 246: @@
 And now there's easy ways to turn off UAC completely.  We'll talk about this more
 later when we talk about security.

Rhooper at 17:59, 16 September 2007

2007-09-16T17:59:36Z

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