“However, the 1st edition was originally published in 1999 and it was definitely showing its age.”
Code walks from Morse code and Braille up to a working CPU, with no hand-waving in between. The new edition adds about 70 pages and goes deeper into the Intel 8080. Petzold’s own tip is to skip the publisher’s website, because the book can’t be found there. Most programmers still can’t explain what happens below their framework. This book fixes that for the price of a dinner.