I remember when I realized I had been using Microsoft all along through my Commodore 64.
"Commodore licensed BASIC from Microsoft in 1977 on a 'pay once, no royalties' basis after Jack Tramiel turned down Bill Gates' offer of a $3 per unit fee, stating, 'I'm already married,' and would pay no more than $25,000 for a perpetual license."
I still remember the ADSR (attack, decay, sustain, release) thing and low pass, high pass and band pass for sound and have some unlikely memories about graphics primitives too for a middle aged bloke!
My original Quickshot II still works. You might bear in mind Daley Thompson's Decathlon was popular in the UK back in the day and it was designed to destroy joysticks.
My C64 now has a USB interface ...