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From: keifer@uiucdcs.CS.UIUC.EDU
Newsgroups: net.micro.pc
Subject: Re: Write protecting a file in DOS?
Message-ID: <24700118@uiucdcs>
Date: Mon, 2-Dec-85 11:31:00 EST
Article-I.D.: uiucdcs.24700118
Posted: Mon Dec  2 11:31:00 1985
Date-Received: Thu, 5-Dec-85 08:31:30 EST
References: <4232@fritz.UUCP>
Lines: 28
Nf-ID: #R:fritz.UUCP:4232:uiucdcs:24700118:000:600
Nf-From: uiucdcs.CS.UIUC.EDU!keifer    Dec  2 10:31:00 1985


Field 3 (byte offset 11) of the file directory entry, bit 0 controls
write protection.  Turn this bit on for write-protect (read-only).

directory entry:
 Field  Offset  Desc.    
   1      0      File name
   2      8      fielanem extension
   3      11     attribute
   etc.

Attribute Byte:
	76543210
	.......1 Read-only
	......1. Hidden
	.....1.. System
	....1... Volume label
	...1.... subdirectory
	..1..... archive
	.1...... unused
	1....... unused

This information is from Peter Norton's "Programmer's Guide to the IBM
PC" (a swell book).

	G. P. Seaburg
	c/o K. Keifer
	Univ. of Illinois