I am a complete sucker for computer coffee table books. This is another one in the Digital Retro school. While that book only covered personal computers, this one goes back to the dawn of computing, and stretches through so that there is some overlap on the PC end.
At first glance, you'd think they're rather similar, but they show a surprising number of differences. While they both have stylish pictures and a little blurb on each machine, they take very different approaches. Digital Retro feels like it's documenting the machines. The photographs are clean, if dry. The text is generally quite informed (perhaps less difficult if you're only discussing modern machines, and you were there are the time). Core Memory is an excuse to take arty photos of old machines. Apparently, they used an award-winning photographer, and it shows. This is not to disparage the work - there's a lot of wonderful detail, to the degree that it's pretty much wires and circuit-board porn, but in places they don't even bother to photograph the machine as a whole, making the context rather mysterious.
On the text side, the words feel uninspiring, but perhaps I've just read too much computer history already. The choice of machines included is appropriate, but uninspiring. I think it would have been great to throw in a few more obscure machines. A few early workstations (maybe a Xerox Star?) wouldn't have gone amiss, maybe a few more DEC machines, too. It also felt incredibly US-centric. None of the early UK computers turned up, and certainly none of the British micros. This was one of the great things about Digital Retro, perhaps a rather useful side-effect of Gordon Laing's UK background.
Having said all this, I think it's a little unfair to just roundly say that Digital Retro beat this book. They are trying to do different things, covering different periods, and I think Core Memory mostly achieves what it sets out to do. And the photos are great.