Re: Write Signal on Disk II Question

["Charlie" <charlieDOTd@verEYEzon.net>]

"Linards Ticmanis" <ticmanis@gmx.de> wrote in message 
news:47384a9c$0$4374$9b4e6d93@newsspool4.arcor-online.net...
> ferdimh@gmx.de wrote:
>
>> Using a '74 one can reencode the signal read from disk and write it to
>> another disk at the same time. Then you only need to step over the
>> tracks while reading and you shold have a working copy (maybe you'll
>> need some circuitry to avoid writing during the seek).
>
> A good idea, however it won't work if you start/end the writing in the
> middle of a sector. The rotation speed is not constant enough to "hit"
> the exact same bit the next time around. So you will need to start/end
> the write in a gap. This means you have to detect gaps. Also, nibble
> counts won't be exact without taking extra measures. So the idea of
> doing this entirely "dumb" is probably not workable.

It might work if both disks were driven by the same motor.  Of course that 
would be a major mechanical hack.

Charlie