> On Oct 24, 2025, at 10:37 PM, ben via cctalk <[email protected]> wrote:
>
> On 2025-10-24 6:29 p.m., Murray McCullough via cctalk wrote:
>> I had forgotten that 75 years ago, Oct. 3, 1950, the transistor was
>> invented leading to integrated circuits making possible personal computers
>> and the interest of our love of computing. Where would we be without
>> Bardeen's, Brattain's and Shockley's invention?
>
> I HAVE NO idea.
>
> When did the point contact diode come out? Radar was the big tech then
> so any use of solid state diodes would be Secret Information.
According to "200 Meters and down" by Clinton B. DeSoto, the silicon and
carborundum "detector" were both invented in 1906, and of course galena (lead
sulphide) point contact diodes were widely used in the early days of radio.
Incidentally, the particular transistor that BBS invented was the bipolar
junction transistor. The field effect transistor is actually quite a lot older
-- patented in 1925 by Julius Lilienfeld, who also invented the electrolytic
capacitor -- but from an article I remember reading as a teenager that one used
selenium and as a result didn't really work. Wikipedia says the first
successful JFET is from 1945; it also cites an article that said the 1925 FET
work used copper oxide, which is a semi-useable semiconductor for rectifier use
known as far back as the 1920.
paul
