Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: version B 2.10.1 6/24/83; site decvax.UUCP
Path: utzoo!watmath!clyde!floyd!harpo!decvax!minow
From: minow@decvax.UUCP (Martin Minow)
Newsgroups: net.arch
Subject: Re: Re: Complement Arithmetic - (nf)
Message-ID: <370@decvax.UUCP>
Date: Thu, 9-Feb-84 17:57:29 EST
Article-I.D.: decvax.370
Posted: Thu Feb  9 17:57:29 1984
Date-Received: Fri, 10-Feb-84 09:08:43 EST
References: <5448@uiucdcs.UUCP>
Organization: DEC UNIX Engineering Group
Lines: 22

The Fortran II run-time library on the 7090 converted blank
input fields to -0.  The 7090 had a 3-way branch instruction
(that's where Fortran's 3-way IF came from), so you could
write

	IF (I) 10, 30, 40
C ... blank field or negative value input
10	CONTINUE
	IF (I .EQ. 0) GOTO 20
C ... negative value input
C ...
C ... blank field input
20	CONTINUE

(I think that's right -- but am too lazy to go upstairs and look
at some of my old listings.)

PS: for your programmer superstition file -- never throw a listing
away; you'll need it someday.

Martin Minow
decvax!minow