* * *Important Messages * * *

Upgrade Service Discontinued

As of Oct-30-2000, I am no longer offering the Double Donkey Kong upgrade service. The original webpage follows for reference only, and will be removed soon.

I appreciate all of the positive comments I have received about the Double Donkey Kong, and hope I have provided a valuable service.
Thank You!

For those interested, click here for info on why I stopped doing upgrades.

Sources for Double Donkey Kong upgrades and complete boardsets

Original Webpage

No upgrades After October 30, 2000
After Oct-30 I will no longer be offering the Double Donkey Kong upgrade service.
Click here for more information.

High score save option now available for Double Donkey Kong.
See below for pricing details.

Double Donkey Kong Multigame

"Double Donkey Kong" is a modified Donkey Kong Junior boardset that plays BOTH Donkey Kong Junior and Donkey Kong on a single PCB set.

No special wiring is required and no special switches are needed! Toggle between games by simply pressing both the player-1 and player-2 start buttons at the same time. Instantly the game will reset and switch to the other game.

The PCB can easily be configured to powerup in either Donkey Kong mode or Donkey Kong Junior mode by moving a single jumper.

This is must have for any Donkey Kong enthusiast!

More information about these two games can be found at the "Killer List of Videogames" (KLOV) database. Donkey Kong and Donkey Kong Junior

dk dk
dkj dkj

Pricing and Availability

Upgrade price through the end of October 2000 is $79 plus return shipping. (This is at a discount from the standard price of $99). Return shipping is $6 if your board does not have the metal mounting plate, $10 if it has the metal mounting plate. Thus you can save on both your shipping and return shipping costs by removing the mounting plate prior.

You send me your working Nintendo Donkey Kong Junior 2-board set and I'll upgrade it to "Double Donkey Kong" and ship it back. See board checklist below to make sure you have a compatible board for the modification. See shipping and packing instructions below.

See important messages at top of webpage page regarding schedule and end of upgrade service.

High score save upgrade option now available for Double Donkey Kong. Gives you all the same features as the DK and DKjr high save kit such as high score save (both games), FREE PLAY, attract mode sound, powerup selftest and on screen settings. Price is a discounted $35, a $10 savings! This option is not user installable and must be ordered at time of upgrade. Click here for details about this upgrade option including screen shots.

Board Checklist

Please make sure the board you are sending meets all of these checklist items. If not, email me, as I might be interested in purchasing your incompatible boardset, or applying it towards the purchase price an already completed double donkey kong boardset.

Board must be Nintendo type (Sorry I cannot guarantee that a bootleg DKJR board can be modified)
Board must be Donkey Kong Junior (Sorry, modification cannot be done on regular Donkey Kong boards or Donkey Kong 3 boards)
40 Pin IC at location 7H (8035) on the CPU board (top board) must be socketed. If this IC is soldered in, please add $5 to help cover the additional labor required to desolder and cost of a new socket. (Note: most boards already have this chip in a socket). Thank You!
Board must be the 2-board type (I'm not even sure if Nintendo even made a 3- or 4-board DKJR set, but I figure I should list it, just to be complete).
Board must be already fully working. Non-working boards will be returned at buyers expense. (Sorry, at this price, I can only accept fully working boards)


The upgrade involves making modifications to both the video and CPU boards. Most of the socketed components are removed and either replaced or re-used elsewhere on the board as part of the modification. A special daughter board is installed into chip location 7H that contains some custom logic. This daughter board has a movable jumper that can be used to configure the initial game that is selected at powerup. At anytime you can toggle between games by pressing both the P1-start button and P2-start button at the same time. The game will instantly reset and toggle to the other version. The new game will start when both the P1 and P2 buttons have been released. Since toggling requires a hard reset, any credits and high scores are lost. Update: See note above for high score save option.

When packing your board for shipment, please be static aware (ie. no plastic bags, no packing peanuts), bubble wrap is OK. The most common thing that breaks during shipment is the video adjustment pots, anything that can be done to protect those will help. If you remove the heavy metal mounting plate (if it has one), the boardset will fit into a (free) standard USPS priority mail shipping box, as well will save you money on shipping in both directions.

When I get the board I will test it using some special diagnostic software. I will then email you back with when I expect to have it completed. I'm getting a lot boards right now as word has gotten out that I'm stopping soon. So it will most likely be 7-10 days from when I get the board to when it will be ready to ship back.

A couple of Double Donkey Kong users have indicated to me that some of the sounds in Donkey Kong mode are slightly different that the orginal sounds. From what they tell me, the Donkey Kong walking and jumping sounds have a slightly higher pitch than the original game, and that the pounding sound during the introduction of the game is slightly distorted. It is not easily noticible unless you have an original DK board nearby to compare too. This is probably an artifact that the game is being played on DKjr hardware, and that each each board has custom hardware to generate each of these sounds. Note, all of the Donkey Kong music is exactly the same as the original game and all of the Donkey Kong Jr music and sounds are exactly the same as the original. Just a slight variation in pitch for walking, jumping, and pounding when playing Donkey Kong.

New!   You can now listen to the difference between the stomping, walking and jumping sounds by clicking here. Special thanks to Michael Bosch of mbdesigns for recording the sounds and building this cool webpage for comparision.

In general it takes me a about a week once I receive the board to complete an upgrade. Depending on how many boards I have in the queue there may be extra delay. I will email you when I receive the board and give you an estimate of when I think it will be completed (shipped). I typically only go to the post office twice a week (Tuesday's and Friday's).

When I recieve the board, I first thoroughly test it using a special diagnostic test fixture. It checks the CPU RAM, the video character RAM, the video sprite RAM, the DMA controller, the interrupt controller. It also verifies all 4 analog sound triggers, all 7 digital sound triggers, and all 14 background music songs. Both characters sets are tested, as well all 4 color palettes. Finally the flip screen and reset hardware are checked. Only if/when the board passes all these tests will I start the upgrade process.

Please keep in mind I'm only doing this in my spare time, between working a typical 40 hour work week and taking care of my two baby daughters.