Recently I acquired an interesting pirate 2 in 1 Famicom cartridge:

On the title screen, you can select two games:

Choice “B= ACT” starts a hack of the game Dragon Ball Z: Gekitō Tenkaichi Budokai for the Datach Joint ROM System add-on, also known as Dragon Ball Z IV (Unl) [U][!] in the GoodNES set.

Side-by-side comparison of the hack and the original Datach game:

In the original game, you have to scan barcode cards to select the fighters. This is of course not possible in the hacked game. Instead, you press “Select” and then a number appears on the screen that can be changed with “Up” and “Down” (the mysterious inscription on the cartridge label “PUSH SELECT PEOPLE TO FIGHT” makes sense now…):

Selecting the number 3031 3233343501 020304050607 has the same effect as scanning the Son Goku character card:

The barcode on the back translates to “022248300117”, by the way:

Scan progress of the original game not displayed in the hacked game:
(Edit: of course the progress is shown in the hacked game, but I forgot to capture it too.)

Scan successful:

The other Choice “A= RPG” starts a hack of the game Dragon Ball Z Gaiden: Saiyajin Zetsumetsu Keikaku. As far as I can tell, the only change made was to remove the copyright information from the title screen:

In case you are wondering about the good quality of the original game’s screenshot – that was made with FCEUX. All other screenshots were made with a video capture card.