Solo Flight (Microprose, 1984)

[toinet]

Solo Flight is an airplane simulator. Select one of the two airplanes and one of the five different flight modes and take off...


PROTECTION TYPE
The disk has a standard DOS 3.3 format with standard markers. Track $22 cannot be copied!


DISK COPY
- Launch your favorite fast disk copy
- Copy the whole disk
Do not pay attention to the read issue with track $22

Now boot the disk... Boing!


REMOVE THE PROTECTION
As it is a DOS 3.3 disk, let's see the catalog... Ooops! The VTOC is located on track $3 instead of track $11. But that is not an issue for Disk Fixer...

- Launch Disk Fixer
- Go to the monitor
- 3792: A9 11 => A9 03
- Ctrl-Y
- Press 'D', the directory command
There are many files but one is named "P", it looks like it is a "P" for "PROTECTION"!
- Edit the file, you will see plenty of $C08C reads. I really believe we have found the protection check...

So what? Let's remove it...

The program is called at $D000 and returns with A=0 when the disk is the original one, or with A=-1 ($FF) if it is a copy.

Let's replace the first three opcodes with our own ones:
- Launch Disk Fixer
- T11/A/4: 18 90 0F => A9 00 60
- Save the sector back to disk

Restart the disk and enjoy...

Toinet