Talk:DOS executable (.com) - Revision history

Darkstar: /* fixed vs relative addressing? */

2013-05-21T18:35:16Z

‎fixed vs relative addressing?

Jonnosan at 08:27, 21 May 2013

2013-05-21T08:27:10Z

Darkstar: /* compressed executable vs commandline program */

2012-12-06T22:22:34Z

‎compressed executable vs commandline program

Maurice.de.rooij at 18:37, 6 December 2012

2012-12-06T18:37:58Z

Dan Tobias: /* compressed executable vs commandline program */

2012-12-06T18:16:29Z

‎compressed executable vs commandline program

Darkstar: /* compressed executable vs commandline program */

2012-12-06T17:22:18Z

‎compressed executable vs commandline program

Maurice.de.rooij: /* compressed executable vs commandline program */ new section

2012-12-06T07:28:44Z

‎compressed executable vs commandline program: new section

New page

== compressed executable vs commandline program ==

Thanks for fixing the initial page. My source, a paper about the file utility mentioned .com files being compressed executables. Guess I should cite more... [[User:Maurice.de.rooij|Maurice.de.rooij]] ([[User talk:Maurice.de.rooij|talk]]) 07:28, 6 December 2012 (UTC)
* [http://scholar.google.nl/scholar?cluster=7943745569952873113 Extensions of the UNIX File Command and Magic File for File Type Identification]

← Older revision		Revision as of 18:35, 21 May 2013
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	While it is unknown what segment a given COM file will be loaded into, it IS known (as specified) that it will be loaded from offset 0x100 into that segment. So intra-segment absolute addressing is perfectly valid. [[User talk:jonnosan\|jonnosan]] 8:26 21 May 2013(UTC)		While it is unknown what segment a given COM file will be loaded into, it IS known (as specified) that it will be loaded from offset 0x100 into that segment. So intra-segment absolute addressing is perfectly valid. [[User talk:jonnosan\|jonnosan]] 8:26 21 May 2013(UTC)
		+
		+	:That's true, the wording could be made slightly clearer. It's not relative vs. absolute addressing itself which is the problem. Relative and "intra-segment absolute" addressing differ only in the instruction opcode used, which the assembler chooses on its own, without the programmer specifying it. Of course, absolute references to fixed segments (c000:0, b800:0, etc.) are also possible in COM files. Feel free to rephrase it :) -[[User:Darkstar\|Darkstar]] ([[User talk:Darkstar\|talk]]) 18:35, 21 May 2013 (UTC)

	== compressed executable vs commandline program ==		== compressed executable vs commandline program ==

← Older revision		Revision as of 08:27, 21 May 2013
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		+	== fixed vs relative addressing? ==
		+
		+	re ''They can only use relative adressing'' - in 8086 mode, a memory address is either
		+	- relative within a segment,
		+	- absolute within a segment
		+	- absolute including a segment address
		+
		+	While it is unknown what segment a given COM file will be loaded into, it IS known (as specified) that it will be loaded from offset 0x100 into that segment. So intra-segment absolute addressing is perfectly valid. [[User talk:jonnosan\|jonnosan]] 8:26 21 May 2013(UTC)
		+
	== compressed executable vs commandline program ==		== compressed executable vs commandline program ==

← Older revision		Revision as of 22:22, 6 December 2012
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	::"Move" exists in the pull-down menu to the right of "View history". I think "Delete" is reserved for admins, though. [[User:Dan Tobias\|Dan Tobias]] ([[User talk:Dan Tobias\|talk]]) 18:16, 6 December 2012 (UTC)		::"Move" exists in the pull-down menu to the right of "View history". I think "Delete" is reserved for admins, though. [[User:Dan Tobias\|Dan Tobias]] ([[User talk:Dan Tobias\|talk]]) 18:16, 6 December 2012 (UTC)
	:: There seems not to exist such thing as compressed executable COM file, after an extensive search on the Google. Because the source was a university paper, I wrongly assumed that it didnt need verification. Another lesson learned... [[User:Maurice.de.rooij\|Maurice.de.rooij]] ([[User talk:Maurice.de.rooij\|talk]]) 18:37, 6 December 2012 (UTC)		:: There seems not to exist such thing as compressed executable COM file, after an extensive search on the Google. Because the source was a university paper, I wrongly assumed that it didnt need verification. Another lesson learned... [[User:Maurice.de.rooij\|Maurice.de.rooij]] ([[User talk:Maurice.de.rooij\|talk]]) 18:37, 6 December 2012 (UTC)
		+	::: Ah, indeed, I didn't see the "move" up there. Could have made my editing a bit more transparent. --[[User:Darkstar\|Darkstar]] ([[User talk:Darkstar\|talk]]) 22:22, 6 December 2012 (UTC)

← Older revision		Revision as of 18:37, 6 December 2012
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	:Ah, yes, that seems a bit wrong (unless they talk about some other, specific COM file). I wanted to add COM some time ago anyway (when I did EXE), but it somehow got lost due to my being busy recently. I just happened to notice it in the "recent changes" and fixed it. On some unrelated note, why can't we delete (or move/rename) any pages? There are a few now that are blanked because they were moved. Is delete/move only for administrators? --[[User:Darkstar\|Darkstar]] ([[User talk:Darkstar\|talk]]) 17:22, 6 December 2012 (UTC)		:Ah, yes, that seems a bit wrong (unless they talk about some other, specific COM file). I wanted to add COM some time ago anyway (when I did EXE), but it somehow got lost due to my being busy recently. I just happened to notice it in the "recent changes" and fixed it. On some unrelated note, why can't we delete (or move/rename) any pages? There are a few now that are blanked because they were moved. Is delete/move only for administrators? --[[User:Darkstar\|Darkstar]] ([[User talk:Darkstar\|talk]]) 17:22, 6 December 2012 (UTC)
	::"Move" exists in the pull-down menu to the right of "View history". I think "Delete" is reserved for admins, though. [[User:Dan Tobias\|Dan Tobias]] ([[User talk:Dan Tobias\|talk]]) 18:16, 6 December 2012 (UTC)		::"Move" exists in the pull-down menu to the right of "View history". I think "Delete" is reserved for admins, though. [[User:Dan Tobias\|Dan Tobias]] ([[User talk:Dan Tobias\|talk]]) 18:16, 6 December 2012 (UTC)
		+	:: There seems not to exist such thing as compressed executable COM file, after an extensive search on the Google. Because the source was a university paper, I wrongly assumed that it didnt need verification. Another lesson learned... [[User:Maurice.de.rooij\|Maurice.de.rooij]] ([[User talk:Maurice.de.rooij\|talk]]) 18:37, 6 December 2012 (UTC)

← Older revision		Revision as of 18:16, 6 December 2012
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	* [http://scholar.google.nl/scholar?cluster=7943745569952873113 Extensions of the UNIX File Command and Magic File for File Type Identification]		* [http://scholar.google.nl/scholar?cluster=7943745569952873113 Extensions of the UNIX File Command and Magic File for File Type Identification]
	:Ah, yes, that seems a bit wrong (unless they talk about some other, specific COM file). I wanted to add COM some time ago anyway (when I did EXE), but it somehow got lost due to my being busy recently. I just happened to notice it in the "recent changes" and fixed it. On some unrelated note, why can't we delete (or move/rename) any pages? There are a few now that are blanked because they were moved. Is delete/move only for administrators? --[[User:Darkstar\|Darkstar]] ([[User talk:Darkstar\|talk]]) 17:22, 6 December 2012 (UTC)		:Ah, yes, that seems a bit wrong (unless they talk about some other, specific COM file). I wanted to add COM some time ago anyway (when I did EXE), but it somehow got lost due to my being busy recently. I just happened to notice it in the "recent changes" and fixed it. On some unrelated note, why can't we delete (or move/rename) any pages? There are a few now that are blanked because they were moved. Is delete/move only for administrators? --[[User:Darkstar\|Darkstar]] ([[User talk:Darkstar\|talk]]) 17:22, 6 December 2012 (UTC)
		+	::"Move" exists in the pull-down menu to the right of "View history". I think "Delete" is reserved for admins, though. [[User:Dan Tobias\|Dan Tobias]] ([[User talk:Dan Tobias\|talk]]) 18:16, 6 December 2012 (UTC)

← Older revision		Revision as of 17:22, 6 December 2012
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	Thanks for fixing the initial page. My source, a paper about the file utility mentioned .com files being compressed executables. Guess I should cite more... [[User:Maurice.de.rooij\|Maurice.de.rooij]] ([[User talk:Maurice.de.rooij\|talk]]) 07:28, 6 December 2012 (UTC)		Thanks for fixing the initial page. My source, a paper about the file utility mentioned .com files being compressed executables. Guess I should cite more... [[User:Maurice.de.rooij\|Maurice.de.rooij]] ([[User talk:Maurice.de.rooij\|talk]]) 07:28, 6 December 2012 (UTC)
	* [http://scholar.google.nl/scholar?cluster=7943745569952873113 Extensions of the UNIX File Command and Magic File for File Type Identification]		* [http://scholar.google.nl/scholar?cluster=7943745569952873113 Extensions of the UNIX File Command and Magic File for File Type Identification]
		+	:Ah, yes, that seems a bit wrong (unless they talk about some other, specific COM file). I wanted to add COM some time ago anyway (when I did EXE), but it somehow got lost due to my being busy recently. I just happened to notice it in the "recent changes" and fixed it. On some unrelated note, why can't we delete (or move/rename) any pages? There are a few now that are blanked because they were moved. Is delete/move only for administrators? --[[User:Darkstar\|Darkstar]] ([[User talk:Darkstar\|talk]]) 17:22, 6 December 2012 (UTC)