Granny and the Gators

1 Introduction

Granny and the Gators was produced in 1984 by Bally. It is one of the few hybrid video/pinball games that were ever produced, and only the second of two hybrid games produced by Bally.

3 Technical Info

3.1 Boards

3.1.1 MPU

This game uses a Bally AS-2518-133 MPU, and is the same as the MPU used in Baby Pacman.

3.1.3 Sound Board

A Bally Cheap Squeak sound board is used in the game. See the main section on the Bally page about this board.

3.1.4 Vidiot Deluxe Board

Bally Vidiot Deluxe Board (Note that this board has been refurbished)

The vidiot deluxe board is responsible for running video portion of the game, accepting input from the cabinet control buttons, and displaying output to the monitor.

Baby pacman had a similar board, but the vidiot board in Baby Pacman and the vidiot deluxe board in Granny and the Gators are different and are not interchangeable.

Note that 1st and 2nd flashes are from the sound board. This is because the sound board and vidiot board share the same line for the LED. If the vidiot deluxe board is being tested on the bench, there will be a 3-4 second delay (to allow for the sound board flashes) before the vidiot board flash sequence begins with the 3rd flash.

4 Problems & Fixes

4.1 Vidiot Deluxe Board

4.1.1 Corroded chip legs

A few of the larger chips may corrode and disintegrate and will need to be replaced. This was typical of certain chips made around this time.

These chips cannot be saved (without extreme measures, such as dremmeling into the plastic to reach clean metal, soldering on new legs, and finally sealing with epoxy).

Additionally, the corrosion can also destroys pads and traces. Be careful when removing the chip from the board--the pads and traces on this board are somewhat fragile.

Replace the chip(s) (new or NOS replacements will not have corrosion issues), repair any board damage, then be sure to do continuity testing to verify there are no broken traces.

4.1.2 3rd flash locks on or does not light

1. Verify that all the incoming and regulated board voltages are correct.
2. Verify that the reset signal goes high and reaches u3 (CPU chip), u27 (PIA chip), u19 (VDP chip), and u28 (VDP chip)
3. Verify that the u9 game ROM is not corrupted and matches the u9 ROM data file. You will need an EPROM burner to read and compare the chip's data to the u9 ROM file.
4. Verify continuity of the u9 socket to the traces on the board. Replace the socket if necessary.
5. Verify continuity of the address lines (A0 through A12) and the data bus lines (D0 through D6) from the CPU to u9.
6. Consider removing, testing, and replacing some of the chips involved with the logic for the 3rd flash, such as u13, u14, u16, and u17. One or more of these chips could possibly be bad.