Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site ucsfcgl.UUCP Path: utzoo!watmath!clyde!bonnie!akgua!sdcsvax!dcdwest!ittvax!decvax!ucbvax!ucsfcgl!arnold From: arnold@ucsfcgl.UUCP (Ken Arnold%CGL) Newsgroups: net.lang Subject: Re: Turing the first? Message-ID: <440@ucsfcgl.UUCP> Date: Sat, 9-Feb-85 13:10:58 EST Article-I.D.: ucsfcgl.440 Posted: Sat Feb 9 13:10:58 1985 Date-Received: Mon, 11-Feb-85 05:13:09 EST References: <8900018@uiucdcsb.UUCP> <18218@lanl.ARPA> <428@ucsfcgl.UUCP> <870@pucc-i> <436@ucsfcgl.UUCP> <888@pucc-i> Reply-To: arnold@ucsfcgl.UUCP (Kenneth C. R. C. Arnold) Organization: UCSF Computer Graphics Lab Lines: 40 Summary: I admit from your quote that the concept of using instructions as numbers was INHERENT in Babbage/Lovelace's thoughts, but I am not convinced that they SAW this. In fact, the idea is inherent in von Neuman's early work, and even in the ENIAC, since it really is inherent in the idea of machine instructions per se. But, to my knowledge, no one before Turing saw this at all, except in the limited sense of instructions which looped through memory. I consider this a major distinction; patents are often issued on things which are inherent in current technology but which nobody happened to see before. We generally credit the individual who saw what was unseen with the invention, not the people who created the potential but did not see it. I still haven't seen anything in Lovelace or Babbage's work that indicates they realized that since the instructions were numbers they could be created by computation as numbers. Turing's ACE did conditional branchings by evaluating an arithmetic expression dependent upon the value being tested. The expression generated an appropriate 'branch' instruction, which was then executed. > "...whenever numbers meaning OPERATIONS and not QUANTITIES > (such as the indices of powers) are inscribed on any column > or set of columns, those columns immediately act in a wholly > separate and independent manner, becoming connected with the > OPERATING MECHANISM exclusively, and re-acting upon this. > They never come into combination with numbers upon any other > columns meaning QUANTITIES; though, of course, if there are > numbers meaning operations upon n columns, these may COMBINE > AMONGST EACH OTHER, and will often be required to do so, just > as numbers meaning QUANTITIES combine with each other in any > variety." [All emphasis in the original] She points out that there is no mix between instructions and data, that they are kept seperate. I took here statement about instruction combining to mean that they are executed in concert. -- Ken Arnold ================================================================= Of COURSE we can implement your algorithm. We've got this Turing machine emulator...