Re: LDA C08C,X

[Holger Picker <pickerh@uni-muenster.de>]

On 24 Feb 2003, Michael J. Mahon wrote:

> Date: 24 Feb 2003 20:37:39 GMT
> From: Michael J. Mahon <mjmahon@aol.com>
> Newsgroups: comp.sys.apple2
> Subject: Re: LDA C08C,X
>
>
> If the third header nibble is not a $96 (for an address mark) and not an
> $AD (for a data mark), then we have not correctly recognized _either_
> header, and we should start over, looking for an address mark.
>
> -michael
>
> Check out amazing quality 8-bit Apple sound on my
> Home page:  http://members.aol.com/MJMahon/
>

I know what you mean, sir, but, I'm afraid, it still does not make sense to
me. Please correct me. I thought when you check for the data mark you will
have already successfully decoded an address header (including checksum).
Chances are zero that you will find another address header with the same
valid information because it would mean that this had been written twice to
the disk. Such a situation could only occure with corrupted disks, e.g.
those which were not formatted correctly or perhaps had some special copy
protection that makes use of this.

Kind regards

  Holger