Re: Disk II Phase Question

["Jplcsch" <jplcsch@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 !
> >
> >
> >
> >
>
>