Jakks Pacific Bass Angler (2005) – Hidden Test Menu Discovered!

 Today I spent some time investigating Jakks Pacific's Bass Angler, a Plug & Play fishing game released in 2005.

This particular game belongs to a rather interesting group of Jakks Pacific Plug & Play titles that use Winbond hardware, with the game's ROM stored internally inside the chip rather than on a separate external ROM.

This makes things particularly interesting from a preservation and emulation perspective. Unlike systems where the game data can simplier be extracted from an external memory chip, these Winbond-based units present an additional challenge when it comes to dumping their internal software.

During today's hardware investigation, I started tracing connections on the PCB, examining the chip-on-board (COB) components, and identifying various test points and signal lines. The ultimate goal is, of course, to better understand the hardware and eventually find a way to extract the internal ROM for preservation and MAME emulation.

But along the way, I made another interesting discovery!

A Hidden Factory Test Menu!

While investigating the game, I noticed that there was practically no information available online about how to access its hidden diagnostic functions.

So I decided to experiment with different button combinations myself.

And I found it!

At the very first Jakks Pacific title screen, enter the following button sequence:

B → C → B → C → A

This secret combination activates the game's hidden diagnostic functions!

Interestingly, the same combination triggers two different diagnostic routines, alternating between them on successive console starts.

Mode 1 – Save Game Test & Memory Clearance

The first diagnostic mode performs a save-game memory test and provides a memory-clearing function. This was presumably intended for factory testing or servicing the unit.

 

 Mode 2 – CRC Verification & Hardware Test Menu

The second mode is even more interesting!

The console first displays a series of CRC verification screens, presumably used to check the integrity of the internal game data.

 After these screens, the system enters a hidden test menu, providing access to diagnostic functions that are normally inaccessible during gameplay.

 

To exit this test menu, simply press:

A + B (simultaneously)

 

Another Little Piece of Plug & Play History Preserved!

It's always fascinating to discover features that have been hiding inside these inexpensive Plug & Play consoles for more than two decades.

Factory diagnostics, hidden menus, undocumented hardware features – they're all small pieces of information that can easily disappear as these devices age.

And while today's discovery doesn't yet solve the challenge of extracting the internal Winbond ROM, it gives us another interesting glimpse into how these games were developed and tested.

One more hidden secret uncovered, and another small step toward preserving these obscure Plug & Play systems!