From: utzoo!decvax!harpo!floyd!cmcl2!salkind
Newsgroups: net.unix-wizards
Title: Re: I/O Error in Push
Article-I.D.: cmcl2.19784
Posted: Sat Nov 13 15:03:29 1982
Received: Mon Nov 15 08:53:05 1982
References: sri-unix.4006

If your disk is (becomes) write protected you will also get this panic.