Custom (fake) & hidden (true) disk directory method?

[JLsoft]

My friend recently dumped some of his old diskettes, and in the batch were some copies of stuff I made around 1992-1994

 

One of the disks from 1994 is a disk-of-the-month we made for our (2 member :P) user group spinoff, and it boots and works fine (accessing multiple 'hidden' files via TurboBASIC)...but it has a custom ATASCII art for the disk directory when it is listed in DOS 2.5/MyDOS/TurboBASIC.  I can see the actual filename info if I look at the disk image in a hex editor/etc, and they're right near the end of the image instead of near the 'middle' where the custom entries are.

 

 

I'm not concerned with getting the true directory entries in DOS in order to copy files/etc, but what I'm really curious about is:

 

...How the heck did I do this??

 

I remember being hyped about having custom disk entries like you'd see on lots of Commodore disks, but I have no idea how I made this.

 

I only had access to a couple Atari 8-bit BBSes at the time, a complete run of Antic magazine, some books like the Compute's Book of Atari series, and a bunch of PD user group disks.

 

So basically I'm wondering if there was some well-known magazine article about hiding a directory...or some free utility for it...or what.  I don't think I worked this out by playing with a sector editor back then...

 

 

 

_{(Sorry, I can't post the image because of personal info in it)}

Edited October 22, 2022 by JLsoft
Typofest 2k22

[baktra]

Most likely you patched the DOS to look for directory in a different sector. The Atascii art is probably result of using a tool from the 'disk editor' category. These tools can edit raw sectors. Decorations are most likely valid file directory entries for files that are 0 sectors long.

[vitoco]

The first time I faced this was in School, when I tried to copy Atari Paint diskette from there for personal use. Without knowing about tech, somehow I got access to the BASIC listing of the main program and found what was happening (poking in some DOS routines to move the directory sector).

 

... and that was how I got involved in hacking, cracking, and programming tools for that purpose. 🤓

[+Larry]

GOTO atarimania.com>Books>Atari Software Protection Techniques and Advanced Atari Protection Techniques.  I'll bet you will find it explained in there.  We used to do that to booby trap some disks -- pissed some folks off, though!

[Mathy]

Hello guys

 

2 hours ago, Larry said:

Atari Software Protection Techniques and Advanced Atari Protection Techniques.

Both books are by Alpha Systems. It's definitely in one of those two books.

 

Sincerely

 

Mathy

 

[JLsoft]

Awesome, yeah, the very first thing in the first book mentions poke-ing 4226 and 4229 to make DOS use different directory sectors, and I see that the Master Memory Map had an example whose values were exactly what I had used to alter the DOS.SYS on this disk

 

I must've seen the trick typed up somewhere or in a user group newsletter or something

 

 

Thanks for the hint!