[Coco] Nitros9 & Mess

[Bill Nobel]

>From: "John Collyer" <johncollyer at zoominternet.net>
>Reply-To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
>To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
>Subject: Re: [Coco] Nitros9 & Mess
>Date: Mon, 2 Feb 2004 16:27:57 -0500
>
>
>First off there is no header information like what you described to
>calculate.
>The emulator checks the .dsk file and if it is not a multiple of 256 it 
>gets
>and
>bleeds off the first byte of the .dsk file and saves it as sectors per
>track. The
>file pointer is now in the correct position inside the virtual file for
>anymore file
>I/O it does. There is nothing to calculate because there is no other header
>information other than this.
>

  I realize this,  The problem is not the .dsk itself,  it's Mess's code on 
how it handles this.
Mess reads the size of the .DSK file, if it is not on a 256 byte boundry it 
uses the very first byte of the file as a sector size for the drive.  This 
is a potential problem as virtual disks are allowed to be zero length on 
startup and expanded as needed.  If you don't start with a .DSK of the 
proper size you will have corruption if your sector size doesn't match the 
very first byte of the file.

  Although I havn't seen any .DSK files with a size problem we shouldn't 
have to worry.  The problem only arises on files not on even 256 byte 
boundries.

-Bill

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