Re: Disk II Phase Question

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

Jplcsch,

    Thank you very much for the information.  I already thought the same 
thing what you said.  I am little disappointed because one last question is 
never answered.  Look at below between asterisk lines.

**************************************************************
    Do each even/odd track have total ($5F00) 24,320 bytes in nibble or 
194,560 bits?
**************************************************************

    It is all I need to know.

Bryan Parkoff


"Jplcsch" <jplcsch@wanadoo.fr> wrote in message 
news:41e8e772$0$19425$8fcfb975@news.wanadoo.fr...
> Many program don't have DOS or PRODOS
> the only thing you need is the sector 0 of track 0 : it must be standard
> because the bootstrap is in ROM (C600) and that's the problem to have a
> perfect protection, it's absolutly impossible ! I explain :
>
> 1. if you write a program (game often) and if you don't need DOS function
> you can put this program on disk as you want, with sectors, codage,headers
> and so as you want, you just need respect the constraints of the disk and 
> of
> the logic sequencer state. It's the reason you found some disk where the
> program is anywhere on the disk, soe part on tracks 1to5 for example an an
> other part on track 10.5 to 16.5, and nothing on the free space. It's to
> cheat the bitcopier in the analyse of every track. In response the
> bitcopiers have some parameters to to a copy corectly but these parameters
> don't drop from sky, a guy examine the real proection and give the
> parameters specific to each bitcoopier. The most acme was Nadol where you
> found a language o drive the copy.
> Look flight simulator : not OS but each track is a long sector of 18 
> pages.
> Look Archon (and some ECA)  you found a track arcing on two tracks
> etc... I speak here about protections with format modifications but other
> techniques existes of course (nibble count for example)
>
> 2. The constraints of the sector 0 track 0 ist the weakness of all
> protections because you can ALWAYS trace the boot. Of course it's not 
> always
> easy to undertand. But the problem is not here, you can mount the programm
> part to part in memory, same parts on disks, disassemble, modify and put 
> all
> on a standard disk even without DOS.
> To trace the boot the way in easy : move bootstrap from C600 to 9600 or 
> any
> address under the pattern X600, modify the jump $801 to a JMP $FF59 for
> example and start with 9600G, the sector is loading at $801, stop the 
> drive
> and look what the loader at $801 do, and continue the bootstrap part to
> part.... many nice articles exists about this method (pirate harbor,
> Krackman etc..)
>
> Now you can understand that standards directories, starndard format or
> DOS/PRODOS is not an obligation.
>
> An easy "protection" (limit stupid and from dumbs protectors) is to move
> directory from $11 to an other track, you can copy of course but can't 
> read
> files with a standard DOS. Every modification to the DOS can be do (look 
> SSI
> with RDOS for example even unprotected in format of the dos 3.3, the RDOS
> stay with all modifications.
>
>
> "Bryan Parkoff" <nospam@nospam.com> wrote in message
> news:k2XFd.13952$wi2.11355@newssvr11.news.prodigy.com...
>> Hello,
>>
>>     Now, I understand how Disk II Drive work.  There is only one
> unanswered
>> question.
>>
>>     Do each even/odd track have total ($5F00) 24,320 bytes in nibble or
>> 194,560 bits.
>>
>>     I suspect that some copy protectioned diskettes do not have DOS 3.3,
>> ProDOS, nor general file and directory structure.  They may not have
>> sectors, or they may have only two sectors each track.  When one sector 
>> is
>> read from track 0, it begins to search for tracks before it reads one or
> two
>> sectors.  One or two sectors are loaded into memory.
>>     It is like audio tape that it does not need file and directory
>> structure.  It may be track to track stream or sector to sector stream.
>> Sometimes, some people claim to be spiral that does not need file and
>> directory structure.
>>     What do you think?
>>
>> Bryan Parkoff
>>
>>
>>
>> "Jplcsch" <jplcsch@wanadoo.fr> wrote in message
>> news:41e82c41$0$7108$8fcfb975@news.wanadoo.fr...
>> >
>> > <mjmahon@aol.com> wrote in message
>> > 1105732032.041520.31230@c13g2000cwb.googlegroups.com">news:1105732032.041520.31230@c13g2000cwb.googlegroups.com...
>> >> Bryan Parkoff wrote:
>> >> > Jplcsch,
>> >> >
>> >> >     Do you mean that head contains a "BIT" scanner which it is wider
>> >> than
>> >> > normal "BIT" scanner?  It looks like it reads and write each 1 1/2
>> >> track
>> >> > instead of 1 track.  You receive valid data from full track while 
>> >> > you
>> >> ignore
>> >> > invalid data from half track at the same time.  Is it correct?
>> >>
>> >> It's simple.  The amount that the head moves radially for one step
>> >> is less than the radial width of the head (the width of the track that
>> >> it reads or writes).
>> >>
>> >> This could be viewed as "overkill" on the resolution of the stepper
>> >> motor,
>> >> or as using a wider head than necessary.  In fact, the signal-to-noise
>> >> ratio of the read signal, and therefore its reliability, is a function
>> >> of
>> >> the track width, and the early media could be quite non-uniform or
>> >> noisy,
>> >> so the use of the "single density" head width was appropriate.
>> >>
>> >> -michael
>> >>
>> >> Parallel computing for a network of 8-bit Apple II's!
>> >> Home page:  http://members.aol.com/MJMahon/
>> >>
>> >
>> > As every time  explications from Michael are perfects !
>> >
>> >
>> >
>> >
>>
>>
>
>