A few thoughts: The historian view is that ENIAC is the "first electronic, general purpose, large scale, digital computer" (with all those adjectives required).

A few thoughts: The historian view is that ENIAC is the "first electronic, general purpose, large scale, digital computer" (with all those adjectives required). The paradoxical thing is that ENIAC is clearly the first in an important way, but it's really hard to nail down how. You really can't overstate the importance of ENIAC: it's the machine that triggered the construction of numerous other computers and started the computer revolution, while earlier systems had very little impact. Another paradox is that although ENIAC directly caused the modern computer, ENIAC was completely different architecturally from modern computers and missing most of the things you'd think of as necessary. It wasn't stored-program or really Turing-complete (although I think those properties are overrated). It didn't have RAM or even use binary or have instructions or programs in the normal sense. Even its inventors recognized that ENIAC's implementation was the wrong approach. But despite all this, modern computers are offspring of ENIAC. My view is that ENIAC's important "first" is that it was the first to show the world that computers were both practical and revolutionary, so much faster that it could solve entirely new classes of problems. As far as the Zuse Z3, the historian view is that the proof that it was Turing-complete "was an impressive party trick, but diverged entirely from the way the machine was designed, how it was actually used, or indeed from anything that would have made sense in the 1940s." If you're interested in ENIAC, the book to read is "ENIAC in Action: Making and Remaking the Modern Computer".