Re: [hatari-devel] HD floppy timing

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On 30 May 2016 at 17:45, Nicolas Pomarède wrote:
>
> I never really checked the accuracy of HD/ED format, since no program is
> known to depend on this (it's not the case for DD where game protections
> expect very precise timing for gap, read sector and so on).
>
> Basically, DD timings to transfer a byte from floppy are divided by 2
> for HD and divided by 4 for ED.
>
> It's quite possible this doesn't give the same values as real HW :)
>
I think I can guess the problem: the emulated HD drives are spinning at twice
the speed of a DD, so a sector miss (extra revolution) takes 100 msec when it
should take 200msec.  Not a problem for games, but it does make Hatari less
accurate as a tool.

Roger




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