NAME:       Tomahawk
PUBLISHER:  DataSoft
TYPE:       Helicopter Simulation

            Cracked from an original by DataWiz/6502 Crew

TECH NOTES:
Tomahawk's copy protection was surprisingly simple, even though it
was published by DataSoft.  DataSoft usually uses a good bit of
format protection in their games, but this one had normal DOS 3.3
track/sector address/data/epilog bytes.  COPYAing the disk did not
lead to a deprotected version though--There was a nice nibble count
routine called twice after the HGR screen is shown.  The nibble
count code was stored encrypted on the disk, and decrypted right
before it runs.  The protector used a simple bit shifting to encrypt
the data, but _tried_ to make the code look confusing:

LOOP:   LDA ($02),y
        PHA
        LSL
        PLA
        ROR
        STA ($02),y
        INY
        BNE LOOP

Needless to say, it made me chuckle. ;-)    
So, to bypass the nibble check, its necessary to NOP out the JSR, but
since its encrypted on the disk, you need to store the NOPs encrypted.
The following are the actual disk patches:

Track 0 / Sector 5
Byte 2B:    From:   40 B0 88
            To:     D4 D4 D4
Byte 3D:    From:   40 B0 88
            To:     D4 D4 D4

That's it, enjoy! --Dw

-----------------------

If you encounter any other apparent protection,
please contact me at datawiz@magpage.com

If you have original apple software that has not yet been
converted to .DSK image format, please contact me.