Apollo Guidance Computer manual details

I've dug out my copy of the manual for the Apollo Guidance Computer. The files total about 165K; I don't think it's appropriate to mail them to the list. But if you want a copy: * Ask me and I'll send you one. * Maybe DejaNews has the posts. * Rich Drushel (who typed in the whole manual!) has a home page at: http://junior.apk.net/~drushel I didn't see the manual there but maybe I missed it. If anyone e-mails Rich and finds he has a later version, please tell me. I also have a separate 24K file (by Rich) with a giant picture of some of the keypads and a bit of extra detail about the AGC. I'm not sure the picture wasn't copied from the manual. The message below was Rich's "foreword" to his posting of the manual. It's fascinating, it's not too long, and Rich can explain the subject better than I can. BTW, I had forgotten the fact that the computer changed over time, each Apollo spacecraft had a few slightly-different "terminals", and the LEM had its own version(s) of the computer. If you want to write a simulator, your work is cut out for you. -- Derek Article 131741 of alt.folklore.computers: Path: news.u.washington.edu!uw-beaver!cornellcs!rochester!udel!delmarva.com!news.internetMCI.com!newsfeed.internetmci.com!howland.reston.ans.net!usenet.ins.cwru.edu!wariat.org!junior.wariat.org!drushel From: drushel(a)junior.wariat.org (Richard Drushel) Newsgroups: alt.folklore.computers Subject: Apollo Guidance Computer (Block I) [0/4] Date: 14 Jan 1996 14:48:02 GMT Organization: Akademia Pana Kleksa, Public Access Uni* Site Lines: 69 Message-ID: <4db532$if8(a)wariat.wariat.org> NNTP-Posting-Host: junior.wariat.org X-Newsreader: TIN [version 1.2 PL2] The Apollo Guidance Computer (AGC) revised 9601.14 by Richard F. Drushel (drushel(a)apk.net) Periodically there are questions on alt.folklore.computers about what kind of computers were used on board the spacecraft in the Apollo moon program. Here are the definitive answers, reproduced directly from the Apollo Operations Handbook for spacecraft SC 012--better known as Apollo 1. After the fire on 27 January 1967 which killed astronauts Gus Grissom, Ed White, and Roger Chaffee, NASA began a massive investigation into the accident. Its 3-volume report, "Investigation into the Apollo 204 Accident", published 10 April 1967, contains not only the accident report, but also a wealth of supplementary data documenting the Apollo Command and Service Modules. Included is the complete Apollo Operations Handbook, which gives blueprints, block diagrams, schematics, theory of operations, how-to-fly-it instructions, you name it--including the computer system. I have broken Section 2, Subsection 2 (Guidance and Navigation System (G&N)) into 4 parts for ease of posting. This is pages 2.2-1 to 2.2-48 of the Apollo Operations Handbook SM2A-03-SC012, or pages 443-488 of Volume II, Part 1 of the Apollo 204 Accident Report. Two of the four figures in this section I reproduce as ASCII art; I've tried to keep it to 80 columns, but in a couple places it spills over, so don't read this with your word wrap on. Of the other two figures, one is a beautiful line drawing, and the other is a 4-page foldout block diagram. If I get around to it, I'll put the text up on my WWW home page and make .GIFs of the artwork. This description of the Apollo Guidance Computer is only absolutely correct for SC 012. A sister ship, SC 014, was completely dismantled during the accident investigation, and some changes were made in the ship design. Also, since SC 012 was a Block I spacecraft, it was never intended to dock with a lunar module--it had no docking probe and tunnel--so any computer programs dealing with translunar injection and lunar orbit rendezvous are absent. As for hardware changes, I don't know if it was due to the fire, but at some point before the manned lunar missions, the Bus A and B voltages were increased from +28 VDC to +65 VDC. This had grave implications for Apollo 13: the thermostatic switch for the heater in the oxygen tanks was never upgraded causing the heater to fail on for 8 hours, baking the inside at 1000 degrees F and exposing the bare wires which shorted out so explosively in space. Other changes from the state of SC 012 include the main hatch (changed after Apollo 1) and the plumbing for the oxygen tanks (changed after Apollo 13). The museum-quality sets in the 1995 Ron Howard film "Apollo 13" show that the Block II computer keyboard was different from that of Block I. I hope to add some ASCII art pictures of this sometime soon. The Lunar Module computer was evidently similar to the AGC. At least it shared the 1201 and 1202 error codes (which occurred during the lunar descent on Apollo 11, nearly causing the landing to be aborted). I have not found documentation similar to the Apollo Operations Handbook for the LM. I've tried to catch all the typos, but some may remain. If you find any, please let me know. Enjoy! I did when I read it; that's why I was motivated to type it all in :-) *Rich* -- Richard F. Drushel, B.A., Ph.D.| ColecoVision AA DDDDD AA M M ===============================| Family A A D D A A MM MM Come to ADAMcon VIII | Computer AAAAAA D D AAAAAA M M M M Cleveland, Ohio U.S.A. | System A A DDDDD A A M M M 5-8 September 1996 |============================================== See the ADAMcon VIII Home Page | http://junior.apk.net/~drushel/adamcon8.html