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From: ROMKEY@XX.LCS.MIT.EDU (John Romkey)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: MIT/CMU PC/IP under Microsoft C V. 4.0?
Message-ID: <12345761316.38.ROMKEY@XX.LCS.MIT.EDU>
Date: Tue, 27-Oct-87 03:12:23 EST
Article-I.D.: XX.12345761316.38.ROMKEY
Posted: Tue Oct 27 03:12:23 1987
Date-Received: Thu, 29-Oct-87 20:26:47 EST
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When we wrote PC/IP, we needed a way to make sure that certain functions
were called when the program exited. Most importantly, we had to shutdown
the network interface and release its interrupt and the clock interrupt.
If you don't do that, the next time you run a program and a network
interrupt happens (like, a packet shows up for you), the PC will jump
off into hyperspace and you'll get a DOS-shattering KABOOM.

So we defined our own exit() routine; no problem, we had control over the
whole standard I/O library for the C (cross-)compiler we were using.

Then Drew Perkins at CMU ported it to MSC, and MSC 4.0 came along, and MSC 4.0
broke the exit_hook() stuff we defined. The right way to fix it is to
get rid of PC/IP's own exit() function and to change exit_hook() to just call
the MSC onexit() function. Don't worry, MSC 5.0 will probably break
this again, as they've renamed it to atexit() in 5.0.

MIT is no longer working on PC/IP. You can get a version of it for MSC 4.0
over the net from CMU; FTP Software also sells a commercial version that
works with MSC 4.0. I don't know the state of any of the other offshoots
of it regarding rolling your own programs.
				- john romkey
				 ftp software
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