R.B.I. Baseball

Secret Message
Only appears in the US version. At the title screen, hold A or B or both then press Start. A staff screen will appear.

Credits Screen
Available only in the Japanese version. Play exactly 10 games, no matter if you win or lose. It can even be the games played in "WATCH" mode by the computer itself. After the 10th game is over and the game returns to the title screen, a credits screen will appear before the team names demonstration.

Debug Monitor
Both regional versions have this cheat. You can enable it in the Japanese version with the button code or with the Game Genie code in the US version.

In the Japanese version, any time during the game, hold Up + Down on controller 1, then press Right, Left, Down, Up on controller 2. In the US version just use the Game Genie code.

A set of numbers will appear at the top-right corner of the screen. The upper four represents the address, and the bottom two are data value at the selected address. Press B (for the Japanese version) or hold Down and press A (for the US version) on controller 2 to enable address and data edit : change any digit using the D-Pad buttons on controller 2, or press the previous combination to save your changes. You can watch any ROM or RAM data and change any RAM data.

CRC Test
There are a series of the Namco games, made by the same programmers Haruhisa Udagawa and Kumi Hanaoka, that contains the same self-test for the data integrity (Babel no Tou, Dragon Buster, Family Jockey, Lupin Sansei: Pandora no Isan, Mappy-Land, Sanma no Meitantei, Sky Kid, Super Xevious: Gump no Nazo, Valkyrie no Bouken: Toki no Kagi Densetsu). Only the Japanese version of this game contains such tests.

To enable any of these tests, you need a special device plugged into the expansion port. The operation of the device is very simple: it should accept the data bit from the data input port and return it back inverted to the output data port. The device consists of 4-bit shift register, working as some sort of FIFO buffer. The input bits goes to the input and then shifted to the output after four cycles.

At the game's boot, it tries to send some special data to the device. If the data output doesn't match the data input inverted, then the game continues the normal operation. But if all data (usually 32, rarely 64 bytes) is matches, self-tests will be performed. The program calculates 24-bit partial checksums for the PRG (excluding the last 8K) and the CHR data, summing only every 15th byte, and comparing it against the etalon.

Before testing of the PRG data, the background color turns red; before testing the CHR data, it turns green. If any of these tests fail, the program will jump directly to the reset routine. It means, one of these tests will be performed infinitely until the special device is unplugged or until the test is passed.

Normally, you'll see the red-to-green flash just before the game's boot, the static red screen if the PRG data is bad, or the flashing red-to-green screen if the CHR data isn't good.

Game Genie code will skip the tests for the special device's presence and jump straight to the integrity tests.