Re: Write Signal on Disk II Question

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

>>     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
>
> Hi!
>
> Do you want to copy the disk to another disk or do you want to make an
> image?
> I don't know a controller CARD, but I can think of a trick with the
> existing card, if you only want to copy to another disk:
> 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).
> If you only want to get an image for an emulator, you could try
> connecting it to the IBM-PC's parallel port. I would connect the Read
> data line to the Acknowledge line (remember it is inverted) and write
> some DOS program to read the signal. IMO this should work but will be
> a very difficult programming job.
> Maybe I'll write such a program when I'm looking for a new challenge.
> Mostly I do these things on an as-needed basis.
>
> Ferdinand Meyer-Hermann

    Are you saying that you try to build a software program to record all 
read pulses from the IBM-PC parallel port?  x86 machine is too fast to 
capture all read pulses from the Apple II disk and put all read pulses into 
binary image.  Flowing read pulses through read signal is limited to 2 MHz.

Bryan Parkoff