I went through a rough patch from 2002 to 2009 and couldn't afford new hardware, other than when I was finally able to get a second-hand laptop.
Before the laptop, I'd go visit customers with my pc tower and ask for peripherals when I got to their office, fun times. Well, not really, but I can laugh now ;)
I don't recall the 386 era and the DVD era overlapping that much…
My 486 had a single speed CDROM but it only had a 500mb and a 100mb hard drive, so still wasn't playing mp3s
The real weird one from that era was the 7 segment led MHz displays that were popular in the 386/486 era. It was weird because the the chips could not change speed in the first place. And I don't want to say every system was like this, but every one I ever saw was set by a set of static jumpers or a dip switch. When you upgraded your cpu you put the little sticker that came with it on the chassis and changed the jumpers, they served the same purpose.
I do remember using it to make older games play less bad, but, as you say, this rarely worked, I think precisely because the speed was never the original one (I don't remember the clock speed of my first PC, but the first one with a turbo button ran at 33 MHz which I'm sure is a lot more than twice the speed of the first one; seems closer to 8x from what a quick search implies).
I knew what it was for and had some old games that ran too fast, but from what I remember, in most cases 16 MHz was still much too fast, so I didn't use the button much.
I think it was no problem to switch Turbo mode on and off in the middle of running software.
I didn’t learn the real purpose until long after they were gone.
The game Titanfall on PC has the audio in it twice, compressed and decompressed. The decompressed was for machines with dual core or less so that there was enough overhead to keep the game running.
Maybe, but there could be other reasons.
In a former life I briefly worked at a game developer, and the PC port of a game we shipped did the same thing. The reason I got was that the assets were just barely too big for the game to ship on one CD-ROM and going to a second disc was going to cost too much. The solution was to encode all the sound assets into .ogg (because it was free and unencumbered) to put on the disc and then convert them all to .wav post-install because the in-house engine couldn't play .ogg files and there was no time to add support before publishing.
Given two files, a compressed file which must be uncompressed to play, and an uncompressed one which does not require extra processing - why would the game ever bother uncompressing te compressed file when the same data is already available uncompressed?
There's no true use case for that that I can see.
In this case it was stated that both the compressed and decompressed versions live side by side. So there is no install size saved.
"The game Titanfall on PC has the audio in it twice, compressed and decompressed."
'has it twice' could just be on the install media, and compressed/ uncompressed chosen as a trade off between install size and performance.
Anyway searching around the OP seems to be misrembering. Titanfall seems to be well-known for 35gb out of the 48gb install being uncompressed audio. I couldn't find a reference to it also having compressed audio also.