December/January 1987 I was doing a vacation EE internship in a power station in Australia. Some of the Hitachi mini computers still used core RAM. This was in an all Hitachi Heavy Industries turnkey coal-fired power station commissioned ca. 1985. Pretty sure they had a reference design from boilers and turbines right down to the hardware and software level and kind of cookie cutter stamped out power stations from it. The Hitachi engineering attitude was obviously "If it works, keep doing it the same way for as long as possible". I was told that for some software (firmware?) updates, they'd simply ship out a new core RAM module -- It's non-volatile after all.
Back in the day you'd go into an electronics store and there'd be books containing just 555 circuit recipes. Not to mention the magazine articles.
And every EE student back when we tied onions to our belts must have had a lab assignment to spec out a PLL using 555 and bits and bobs and then measure transient responses, temperature stability, etc.
The world would be a much sadder, drearier place without the 555. That's the nostalgia part out of the way.
Really it's such a useful almost universal lego block of a component that it's hard to imagine it going away anytime soon. Sure microcontrollers are as cheap as chips these days, but you get a lot more with them. Do I need to say that sometimes more is less? Can think of scenarios where you absolutely don't want to see a chip containing firmware/code which needs auditing and locking down.
Back in the 1980s2H there was a brief fashion trend of woollen knit sweaters with IC mask type patterns. Guessing related to designers playing around with design software and knitting tech made possible by microprocessor revolution.
I wasn't making point about mathematics qua mathematics. Was thinking that if I were doing EE undergrad today, I'd use SageMath or Mathematica to crunch the mechanical algebraic manipulations involved in doing a z-transform.
When I did EE, didn't have access to any kind of computer algebra system. Have 'fond' memories of taking Laplace transform transfer functions and converting to z-transform form. Expand and then re-group and factor. Used a lot of pencil, eraser and line printer fanfold paper for doing the very basic but very tedious algebra. Youngsters today don't know how lucky.. (ties onion to belt, etc., etc.)
Bingo. We certainly learned about Cooley-Tukey in undergrad back then. That power station was 100% Hitachi Heavy Industries turnkey. The control rooms had Hitachi mainframe and some minicomputers running proprietary real time OS (I guess). These were the days when the video controller for a colour industrial process control raster display CRT was a waist-high cabinet. So you'd transduce the flicker and then transmit it via analogue current loop to a rack in the control room annex, convert back to voltage, A/D it... and crunch the FFT on one of the control room computers. Something like that. Cheap distributed compute just wasn't a thing at the time.
In the late 1980s I did an electrical engineering internship in a coal-fired power station over summer vacation. The gas furnace igniters ran continuously, but how do you detect presence or absence of burner flames against semi-apocalyptic background of ignited pulverised coal dust being air-blasted into the furnace? Have a little window and photosensor pointing at the burner flame and FFT. No spectral component spike at xHz (IIRC x ~= 13? -- it's a burner flame, underlying dynamics not same as for candle wick) --> ringing alarms, flashing lights.
My first thought was to upload the PDF to Qwen3 and ask it to reimplement in Python using NumPy, Astropy, etc. Have to work on the day job, but could be some educational fun learning and Jupyter plots in my near future. Anyway, the generated code looks promising and contains the requisite green tick and bar graph emojis, so what's not to like?
Now where's my pony?