In the early days, PNP bipolar transistors were common, but the bulk of circuits you see today use NPN transistors. As [Aaron Danner] points out, many people think PNP transistors are “backward” but ...

[Dr. Cockroach]’s goal was to build a four-bit computer out of recycled and repurposed junk. The resulting computer, called IO, consists of a single 555, around 230 PNP and NPN transistors, 230 diodes ...

The ISL73096EH is a radiation hardened ultra high frequency NPN/PNP transistor array. It contains three NPN transistors and two PNP transistors on a common substrate. The device covers all of the ...

In 1964, when I started working in the electronics industry, a single silicon transistor cost over £1 ($2.80 at the time, or about $22 at 2014 prices). These cheap ones were not very good and higher ...