Un repas francais (DC Heat, 1984)

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#1015 - A disk imaged by 4am at Kansasfest 2019. Thank you for the disk images. It is an eduware to learn French using food and friends.

Disk structure
It appears to be two single-sided DOS 3.3 16-sec disk. T22 cannot be read. The usual VTOC on T11/S0 is on T16/S0. The catalog is on T11/SF (and that is normal)

Protection type
A deeper analysis with the nibble editor of Copy II Plus shows that:
- T22 is formatted with FF nibbles only, its length is less than $1000 bytes
- T23 is formatted with AA nibbles only, its length is less than $1000 bytes
A perfect place for nibble or nibble length on-disk protection check.

How to copy
Boot my copy disk. Launch Advanced Demuffin 1.4. Press P to bypass boot.
Format a disk on D2.
Convert 16-sec disk from T0/S0 to T21/SF of both sides.

An alt. way is to use Locksmith Fast Disk Backup to copy both sides.

Is there a protection check?
With Disk Fixer, we search for BD 8C C0 on the two sides.
We find a couple of answers on T1/SC, and that is not normal, so there's a protection check here! Standard uses of BD 8C C0 is on T0.
The protection check is described later in the thread.
We understand from the code that it lies at $AD37.
It is called at $AD2B on T1/SC.
But $AD2B is not called.
So, there is a protection check but I see no call to it.
As the call may happen later in the eduware, we'll patch the entry point.

How to normalize
On side 1, using Disk Fixer

[toinet]

The on-disk protection check on T1/SC