[cpu86] did use some PNP transistors to give him the ability to turn off some of the 555’s to get everything working correctly. He explains the use of two’s complement in the subtracting ...

The transistors being made by Bell just didn't work the same way twice, and on top of that, they were noisy. While one lab at Bell was trying to improve those first type-A transistors, William ...

The first transistor was about half an inch high. That's mammoth by today's standards, when 7 million transistors can fit on a single computer chip. It was nevertheless an amazing piece of technology.