Re: Direct access to disk drive in DOS 3.3?

["Jayson Smith" <nospamratguyspambegone@nospamplease.bellsouth.ihatespam.net>]

The emulator I'm using is called A2, and was written by Rich Skrenta.  The
reason I use that is because I'm blind and can't use modern emulators that
use graffics libraries to draw the screen.  A2 uses pure text.  The downside
is that it only emulates an II+.

"Laine Houghton" <laine@intergate.com> wrote in message
10kbd4bqktj8h6e@corp.supernews.com">news:10kbd4bqktj8h6e@corp.supernews.com...
>
> "Jayson Smith"
<nospamratguyspambegone@nospamplease.bellsouth.ihatespam.net>
> wrote in message news:F081d.53980$Np2.19386@bignews4.bellsouth.net...
> > Hi there,
> > What's the easiest way in a machine language program to access the 5.25
> disk
> > drive directly E.G. not via RWTS?  I have one application in mind
already.
> > I'd like to be able to make a copy of a copy protected disk.  Yes, I
know
> > that programs E.G. copy II Plus do this, but I happen to know where the
> > protection is stored.  It's stored in track 2, sector 15 of the disk, in
> > such a form as to produce an I/O error under Dos.  The strange thing is
> that
> > the program works just fine on the emulator I use.  I guess the
protected
> > sector is read correctly by ADT but you can't just copy that to another
> disk
> > using RWTS as it would no longer produce an error.  So what would be the
> > easiest way to write a program, either in machine language or in Basic
> using
> > a machine language call, to read in that sector and write that same
> sector,
> > complete with errors, to the same sector on another disk?
>
> It would be interesting to see what you get with the prodos read block /
> write block commands. Very little code required and the ref manual gives
you
> the formula to determine what track-sector each half block corresponds to.
>
> What emulator are you using?
>
> track 2 sector 15 of the disk should reside in second half of block 23.
>
>        ORG $300
>        JSR $BF00  ;MLI CALL
>        DFB $80     ;READ BLOCK
>        DFB $09,$03 ;PARAMETER LIST ADDRESS
>        BCS  ERROR ; REPORT PROBLEM
>        BRK              ; CRASH INTO MONITOR AND EXAMINE DATA
> ;$0309:
>        DFB $03   ;PARM COUNT
>        DFB $60  ;SLOT 6 DRIVE 1 USE $E0 FOR DRIVE 2
>        DFB $00,$10 ;$1000 DATA BUFFER, SEE NOTE
>        DFB $17,$00  ;BLOCK 23
>
> ;NOTE: track 2 sector 15 starts at $1100
>
>