Talk:Apollo Guidance Computer
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CCS instruction background
Fascinating article. Would love to know what the thinking is behind the CCS instruction - what sort of problem does it solve? What would be a modern (C, say) equivalent contruction? GRAHAMUK 04:51, 2 Sep 2003 (UTC)
- The CCS instruction can be used to perform the equivalent of the C language "if" statement, "switch" statement, "for" loop, or "while" loop. I was going to put a code fragment in here as an example, but the editor really mangles the formatting... --Pultorak 07:29, 4 Sep 2003
- The code fragment would be interesting, and could be adequately formatted in Wikipedia by putting a space first in every line. If applicable, you might get it back via the Page history link and put it back in. --Wernher 00:34, 3 Mar 2004 (UTC)
- Designer's comment: I could probably write a small book on CCS alone. Let me know if my amplifications in November left anything unanswered. Did I mention that the basic idea was lifted from the IBM 704/7094's CAS (Compare Accumulator with Storage)? --67.75.8.160 02:46, 1 Mar 2004
- First: a question before going into the subject matter proper: does "designer" in the above comment by any chance relate to "designer of the AGC and/or its instruction set"? Just wondering. And now to the question at hand: maybe the 7090/94 heritage should be mentioned in the article, in the 'quest' of educating readers about the sometimes hidden, and of varying degree and significance in each case, but still often very fascinating, continuity underlying much of computer development history? --Wernher 00:21, 3 Mar 2004 (UTC) / 21 Apr 2004
Single/double precision
The "single" and "double" precision mentioned in the article links to IEEE definitions, but surely the author meant one or two of the 15/16-bit words the machine used? --Anonymous, 21 Apr 2004
- Thanks for mentioning it, I have to admit I didn't think of that when inserting the links. :-) However, the opening paragraph of the respective 'IEEE articles' does actually define sgl/sbl precision fairly generally (i.e. using one vs two words), so hopefully we'll avoid misleading the readers too much. Eventually I think we should 1) make a separate article on general single/double precision numbers, and 2) incorporate even clearer introductory info, w/links to the general article, in the IEEE definition articles. --Wernher 16:13, 21 Apr 2004 (UTC)