5 Jun
2014
5 Jun
'14
10:35 a.m.
the mac and lisa 400k drives did the same thing. what i've heared is
that one of the sound channels was used for this. the other being the
mono sound out port.
On 04-06-14 21:25, Tony Duell wrote:
--
Met vriendelijke Groet,
Simon Claessen
drukknop.nl
I was looking
at it from a conventional viewpoint--with the disk turning
at a constant speed, which is the way most people view them today.
Saying "variable speed spindle" doesn't convey quite the same level of
arcaneness to me.
I think a disk turnign ant differnet speeds to read/write different
tracks is somewhaat more arcane than a changing data rate.
However , the origianl Sirius drives were varaible rate. I don't have
the scheamtic to hand, but IIRC there's a microcontroller (8048?) that
takes in a 4 bit speed value for each drive, takes in the tacho signals
and outputs a cotnrol signall to the motor driver. And yes, you can hear
the speed change ans youformat a disk.
-tony