This is a method devised by Fiveways Software. It is found on several Heineman titles, for example.
The catalogue cannot be viewed due to VDU21 and VDU23 characters in the disk title. When *CAT is used the string (c)FWS appears and the computer appears to hang.
There is only one file in the catalogue, !BOOT. This is a machine code file resident at &7000 to &7FFF.
The !BOOT file handles a lot of the protection mechanisms. Amongst other things !BOOT does;
The code at &700 is responsible for loading files from the disc surface and decrypting them by adding &41 and EORing with &97. The new FILEV points to this code.
The RAM-based disk catalogue at &E00 to &FFF is modified to include an entry for a BASIC file called A. This is CHAINed and uses the code at &700 to *LOAD the needed files and decrypt them on the fly. These files are then moved down in memory and RUN.
In addition tracks 1 and 2 are specially formatted. Track 2 is formatted with 1 sector of 128 or 256 bytes and numbered 147. Track 1 is formatted as 8 sectors of 256 bytes if Track 2 is formatted with one sector of 256 bytes or one sector of 2048 bytes if Track two is formatted with one sector of 128 bytes. Track 1 is deleted data.
Most of the other tracks are deleted data but even amongst those there is the odd track that is normal data.
Tracks 24 onwards are not formatted.
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