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quux | 1 month ago

The designers planned on using a shift register in the 6522 VIA chips to implement fast serial loading, but an undocumented bug in that chip forced them to fall back to the slow bit banging version that shipped

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deater|1 month ago

I don't know how many of you have seen a 1541 floppy drive in person either but it is massive, it's heavier and possibly bigger that an actual Commodore 64 and pretty expensive at the time too.

it's fun seeing c64 people on the defensive about it, a nice change from getting lectures from them about how their graphics were the pinnacle of 8-bit computing

badc0ffee|1 month ago

Part of the size was the internal power supply. And that thing got hot, too. I used them at school, but at home only had the smaller 1541-II with an external power brick.

The Apple II disk drives, on the other hand, were not only cheap (Apple was different then!) and fast, but were powered by the ribbon cable connecting them to the computer.

rasz|1 month ago

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|1 month ago

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|1 month ago

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!