Double Donkey Kong    High Score Save Kit -- Installation Guide

Step 0: Turn off power to the game

It is recommended that you remove your boardset from the cabinet before making the modifications as it requires soldering one wire. When removing the boardset, pay careful attention (or label), any wire connections as you disconnect your board so that you can correctly rehookup the game PCB afterwards. If your board uses the large 44 pin edge connector, take note of which side of the connector if facing the parts side of the board and which side faces the solder side, This connector is typically not keyed and can be inadvertantly plugged in backwards - ouch! It is recommended that you label the connector faces with something like "parts side" or "solder side".

Step 1: Locate the CPU board

This is the board which has the edge connector as well it has the Double Donkey Kong sound daughter card.
Double Donkey Kong (Junior) CPU board

Step 2: Remove the Z80 CPU chip

Locate and remove the Z80 chip on the CPU board. It is located a row/column 7C. Remove the chip gently by using a flat head screwdriver to pry it out of its socket from each end. Becareful not to bend any of the pins. If any pins do get inadvertantly bent, you will need to straighten them out before the next step. Needle nose pliers work the best for this.

Step 3: Insert the Z80 into the daughter card

Insert the just removed Z80 chip into the empty 40 pin socket on the High Score Save Kit. Make sure pin-1 is correctly oriented. Pin-1 is marked on the Z80 chip usually by some type of indentation or circle molded into the plastic. The end of the chip with the marking, needs to match up with the socket on the daughter card that also has a marking on the plastic. Pin-1 is also labelled on the kit pcb with a "1".
Pin-1 Identification
Click images for a larger view
Z80 CPU Chip
High Score Daughter Card
Pin-1 Identification

Step 4: Insert the daughter card into the CPU board

Insert the daughter card back into the Z80 socket on the CPU board where the Z80 chip was originally removed from. Again, make sure pin-1 of the Z80/daughter card is oriented to correctly match pin-1 on the CPU board. Use the photos as a guide.

The header on the daughter board has pins that are more heavy duty than the original Z80 pins, thus you will need to press very firmly to get the daughter card to be fully inserted into the original Z80 socket.

Step 5: Solder the "select" wire

The lose wire that is attached to the DDK high score save kits needs to be attached to the existing daisy-chain "select" wire that interconnects all of the DDK eproms. It can be attached anywhere in the chain.

I'm currently suggesting that it be connected to the solder glob that is on eprom chip 5E. Using your soldering iron, touch the connection at 5E to melt the glue, clean it off with a paper towel, as well clean you soldering iron tip too. Once the glue has been removed, wrap the lose wire around the connection several times, and then reflow the solder connection. You might want to add a little extra solder.

It is also suggested that you glue or tape the wire to the boardset so that it inadvertantly does not get snagged or broken.

Step 6: Double check your work

Review the steps and double check that Z80 is properly installed into the daughter card with no bent pins and that it is correctly oriented for pin-1. And that the daughter card is also installed snug into the z80 socket with pin-1 matched up. Lastly, verify the select wire is attached.

Step 7: Powerup and game and enjoy!

Reinstall your board into the cabinet, and then powerup your game. You should immediately see the bootup screen. Verify the correct title "DOUBLE DONKEY KONG" is displayed at the top. You will have 5 seconds to press P1 and enter setup mode, or the game will timeout and automatically transition to gameplay mode.

If the game does not come up, turn power off immediately, double check your work, and read over the trouble shooting section.