Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site ames.UUCP Path: utzoo!linus!decvax!tektronix!hplabs!well!ptsfa!dual!ames!eugene From: eugene@ames.UUCP (Eugene Miya) Newsgroups: net.columbia Subject: Re: Old fashion computing practices @ NASA Message-ID: <1088@ames.UUCP> Date: Thu, 15-Aug-85 20:13:32 EDT Article-I.D.: ames.1088 Posted: Thu Aug 15 20:13:32 1985 Date-Received: Mon, 19-Aug-85 21:30:34 EDT References: <1079@cbdkc1.UUCP> <46@escher.UUCP> <239@pyramid.UUCP> Organization: NASA-Ames Research Center, Mtn. View, CA Lines: 35 > > I thought the shuttle software was done by Intermetrics...? > the compilers? In general, how can one find out more about computing on the > shuttle? > -- > -m------- Carl S. Gutekunst, Software R&D, Pyramid Technology Again best reference was the CACM several months ago on the shuttle CPUs [IBM], and the recent issue of the Annuals of Computers. The programming language developed by Intermetrics for NASA in 1973 is called HAL/S. I have a manual [since you are in Mountain View] if you want to read it. It is supposed to be "FORTRAN-like" but after inspection it is closer to PL/1 without dynamic memory and other sophiticated features, oh yeah, there is no multiple operator '*' instead two adjacent variables are multiplied like in algebra [big mistake!]. Intermetrics modified HAL/S into a real time ground form called HAL/G. They also tried to submit a modified version as a candidate language for Ada and was one of the four finalists. There is a HAL/S user's group run by an old friend, but only NASA uses it to any degree. HAL/S is written in PL/X or something and was hosted on 360/370s for cross compilation to the Shuttle's computers. My short bit of work was to help evaluate whether it was worth $1 million to spent hosting HAL/S to Univac 1100/81s for Galileo's onboard computers. NASA is now considering Ada for future space work, but the dynamic memory and lack of instruction space on most spacecraft computers has old timers talking about a restricted Ada. [e.g. "Oh no! . . . recursion is inefficient, dangerous, and difficult to comprehend...." much less pointers] --eugene miya NASA Ames Research Center {hplabs,ihnp4,dual,hao,decwrl,allegra}!ames!aurora!eugene emiya@ames-vmsb