Zuse and stored-program

http://www.epemag.com/zuse/part4a.htm Funny, one of the fore-mentioned URLS on the Z3 state that it wasn't stored-program, but there's also this tantalizing tidbit from the page: "Due to the fact that he wanted to calculate thousands of instructions in a meaningful order, he only used the memory to store values or numbers." I wish I could remember where I read that Zuse thought stored-program and self-modification of programs was, in effect, Wrong, not simply 'not a good technical idea'. The above quote is strange, it implies to me that if programs and data are in the same store, the resulting program would 'get out of order'. We know that of course this IS possible (bugs, self-mod ruins a program, etc) but somehow we've learned to carry on in spite of this horrible limitation. Even von Neumann originally thought self-mod a problem -- if you read the original (not later edits) of the EDVAC paper you'll see he specifies a bit of memory-content to differentiate data vs. program, to prevent programs from changing themselves. It was soon dropped though, I'd have to look up the dates, but by the time anything got built the data/prog bit was gone. JvN got a lot of cred for the 'stored program' concept but I can tell you from reading original materials (1938 - 1945) that it was a very well understood concept at the time (hell it's bloody obvious when you sit down to write up a design; memory is a huge stumble, and re-using your sole store cuts size in half at slight increase in complexity, no matter how insightful you were about what you were doing), he was the first to record it, maybe, but he didn't think it up. Note that he never claimed to have, either. In fact I'd go so far as to say that JvN didn't really get computing *at all*. He was a terrifyingly brilliant man, but he also was savvy enough to not persue areas in which he was not top-of-the-pile; he curtailed his involvement in computing pretty early. The data/prog mem bit thing is in here somewhere http://wps.com/projects/EDVAC/index.html but I don't feel like reading it all again. In fact, I'll go so far as to say that few people, even those BUILDING machines, really had any idea what they really were. Turing knew, and said so -- the ACE REPORT even states that electronic computers don't "do" arithmetic, they "simulate" it, that's good enough, it's all about manipulating symbols, not counting and arithmetic, yet look at the instruction sets of machines ACTUALLY BUILT; they SUCKED at symbol processing. Hell my LGP-21 barely has an AND instruction, no OR, no right-shift (except hardware divide). Look at all the EDVAC-thread machines that *got built*; look at Turing's ACE design vs. what got built in Pilot ACE (they took out all the logical instructions he designed in!) Hardware complexity is not the reason; the low-level logical stuff is the easiest to implement -- it's basically free, without carry an adder does OR, float augend in it does NOT, set carry+float augend it does INCREMENT, 2's-COMPLEMENT, etc etc. In fact, I asked a few of our grad students, programmers all (!) 'what a computer is' and/or 'what makes it unique' and even today, few either have the knowledge or perspective to know it's 'the machine that modifies itself'. Sheesh.