[rasz]

Oh its MUCH better than that. Commodore did this because they had incompetent management. They shipped earlier products (VIC-20, 1540) with hardware defective 6522, but:

- C64 shipped with 6526, fixed version of 6522 without shift register bug

- C64 is incompatible with 1540 anyway

They crippled C64 and its floppies _for no reason_.

[timbit42]

It was not for no reason. When adding a screw hole in the motherboard so it could be mounted in the case, they accidentally removed the high speed wire, dooming the C64 to the same slow data speed of the VIC-20 with it's faulty VIA.

The C64 data speed actually ended up being even slower than the VIC-20. You can read the full detailed here: https://imrannazar.com/articles/commodore-1541

[quux]

ah yes, you're right, they did try to fix it in the C64, forgot that whole part of the story.

They finally got it right in the C128 though!