12 Jun
2023
12 Jun
'23
1:06 p.m.
On Sun, Jun 11, 2023 at 09:21:52AM -0600, ben via cctalk wrote:
[...]
I would of thought the AMIGA would have a say here, as
it reads a disk
track as just a bunch of flux transitions.
The Amiga has a choice of two fixed clock rates, both of which happen to
correspond with common DD disk formats of the day. A (digital) PLL is used
to nudge the frequency to synchronise with the incoming flux transitions
when reading, but that's to handle wow and flutter, not formats using a
different clock.
This is sufficiently-limiting that the Amiga cannot use standard HD drives,
but needs a special drive which drops to 150RPM when HD media is inserted so
that the clock speed remains the same.