UNIX (c). It usually works.

[utzoo!decvax!harpo!seismo!hao!cires!nbires!ut-ngp!jsq]

I thought it looked familiar,
so I asked the most likely culprit.
I suppose I should remark that he was referring
to pre-phototypesetter C and V6 Unix at the time.

>Return-Path: <dan at bbnp>
>Received: from bbnp by utexas-11.arpa ; 12 Apr 83 16:19:47 CST
>Date: 12 Apr 1983 17:13:15 EST (Tuesday)
>From: Dan Franklin <dan at BBN-UNIX>
>Subject: Re: Usually?
>In-Reply-to: Your message of 12 Apr 1983 15:40 CST
>To: John Quarterman <jsq at utexas-11.arpa>
>Cc: dan at bbn-unix, smoot at utexas-11.arpa
>
>Gosh!  I really, really, wish I'd put my name on the damn thing!
>Could you send a message to net.lang.c mentioning that I wrote it?
>
>I'm impressed that the attribution is correct as far as it goes.