4 ms·

Interesting. I had the impression, the turbo button was created to slow down new PCs, so they could run old software that relied heavily on CPU speed.

• weinzierl 1y ago
  Yes, originally it was added to slow down faster XTs to exactly the 4.77 MHz of the original IBM XT. With the AT it usually slowed down to some arbitrary frequency and it was more like a gimmick.
  • sitkack 1y ago
    Afaik it was to interface with bit banged hardware that couldn't communicate at the faster rates. One would turn off turbo to print.
    • weinzierl 1y ago
      That is why I think it made sense when it switched to exactly 4.77 MHz but the arbitrary frequencies introduced later were just a toy.