On 06/05/2018 01:29 AM, Christian Corti via cctalk wrote:
Just a guess, but 556 kHz is 5 MHz divided by 9.
Actually, it's a repeating decimal 555.5555....
And we're talking bits/chars per inch, so I don't see the connection,
particularly on a 75 ips drive.
More guesses welcome! This one's been dogging my mind for nearly 50
years, so I'm the patient sort...
--Chuck