[linux-audio-dev] Final Scratch, custom kernel?

[Cornell III, Howard M]

What am I missing here?  I don't mean to tell the direction from the time,
but to tell the position from the time.  The sawteeth all look the same,
right?  Don't we need to tell position somehow?


-----Original Message-----
From: Steve Harris [mailto:S.W.Harris at ecs.soton.ac.uk]
Sent: Tuesday, October 08, 2002 8:59 AM
To: 'linux-audio-dev at music.columbia.edu'
Subject: Re: [linux-audio-dev] Final Scratch, custom kernel?


On Tue, Oct 08, 2002 at 07:17:43 -0600, Cornell III, Howard M wrote:
> But encode the time so that it can be read forward or backward.

You dont have to, because you know what direction its being read in from
the saw.

An obvious problem is if you jump, then hold the disk and let it turn
slowly, it might take a fair turn before the position can be read...

45rpm = 1 1/3 sec per rev

assume 2400 baud timcode, 16 bits of timecode info (inc. stop bits etc)
= 13.3ms for 2 whole timecode blocks

therefore (max) 1/100th of a revolution to pick up the timecode position
= 1" at the edge of a 12" record. min would be 1/2"

hmm... that doesn't sound too bad to me, and you may be able to get better
than 16bits @ 2400 baud.

- Steve