*BSD News Article 28119


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From: stark!gene@newsserv.cs.sunysb.edu (Gene Stark)
Newsgroups: comp.os.386bsd.questions
Subject: Re: PDP-11 Executable?
Date: 7 Mar 94 07:42:28
Organization: Gene Stark's home system
Lines: 12
Message-ID: <STARK!GENE.94Mar7074228@stark.uucp>
References: <2ldnu7$8v1@news.ysu.edu>
NNTP-Posting-Host: home.stark.cs.sunysb.edu
In-reply-to: ap713@yfn.ysu.edu's message of 6 Mar 1994 23:11:03 GMT

In article <2ldnu7$8v1@news.ysu.edu> ap713@yfn.ysu.edu (Christopher L. Mikkelson) writes:

>   Just out of curiosity, is there any reason that a .o file (Under FreeBSD)
>   looks like a PDP-11 Executable to 'file'?

Because the first 16 bits of the file are octal 0407, which was the
original magic number for PDP-11 executables.  It also happens to be
a PDP-11 branch instruction, whose purpose was to jump around the header
information and begin execution at the "real" beginning of the program.

							- Gene Stark
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