Re: Write Signal on Disk II Question

["Bryan Parkoff" <nospam@nospam.com>]

>I think you are thinking that more data can be encoded than is done with 
>the present scheme.  It might be an interesting achedemic exercise and if I 
>were you, I'd study the QAM modulation schemes often used in broadband 
>communications.   However keep in mind that there is only 1 write output 
>control to this drive, there is very limited bandwidth on a floppy 
>interface and a relatively low signal to noise ratio, so you are very 
>limited to what can be achieved.
>
> see http://en.wikipedia.org/wiki/Quadrature_amplitude_modulation

    I understand the limitation.  Most copy-protected programmers always 
write disk bytes to the disk using more than two adjusted zero bits 
reliably.  Then, the copy-protected disk runs using read sequencer without 
any problems.  Most crackers are unable to read more than two adjusted zero 
bits by attempting to copy to the destination disk.  Is it true?
    Do you know any special controller card without using logic state 
sequencer ROM may be able to read all presence pulses and absence pulses 
reliably?  All presence pulsea and absence pulses can be written to the disk 
reliably using special controller card.  Do you know if it exists?

Bryan Parkoff