To expand on what pinewurst said, the Alto was built minicomputer-style out of TTL chips, so even with minimized hardware the CPU took three large boards of chi

To expand on what pinewurst said, the Alto was built minicomputer-style out of TTL chips, so even with minimized hardware the CPU took three large boards of chips. Within a few years, microprocessors took over and Moore's law crushed computers built from discrete chips. Here are some bonus pictures of boards from the Xerox Dorado, which used ECL chips for higher speed. First is the ALU board; the large chips are ECL versions of the 74181 ALU. Second is a detail of chips from the 10K family, as well as unusual square memory chips. https://lh3.googleusercontent.com/--KYoSBUuOhg/V4Rxs7tLB-I/AAAAAAAA4vM/_HY8Xvkg0DgRjl36M4ZyjY5PYXrvlWh2gCCo/s800/alu.jpg https://lh3.googleusercontent.com/--KYoSBUuOhg/V4Rxs7tLB-I/A... https://lh3.googleusercontent.com/-MWYhn7enXdA/V4RxsQ8YHRI/AAAAAAAA4vI/5hAeS8i7ZX8M3DNANpXNrcXStB3_0qZmACCo/s800/square.jpg https://lh3.googleusercontent.com/-MWYhn7enXdA/V4RxsQ8YHRI/A...