Donkey Kong Junior - Flip Screen Hacks

Donkey Kong and Donkey Kong Junior, both have designed into the boardset straps which can be cut and jumpered that will flip the screen 180 degrees from normal. Below are two hacks for DKJR. Donkey Kong has a similar (but not identical straping structure).

The DKjr boardset has designed into it a place that functionally would hold a SPDT switch. This switch either selects the standard flip signal, or the flip signal after it has been run through an inverter.

Hardwired flip screen hack - simplest

In the corner of the CPU board and nearest to the white power interconnect connector locate a yellow rectangle with some solder pads.

Look for the text SL6 and CL9

In its factory state, the pad at SL6 will be OPEN (not connected), and the pad at CL9 will be CLOSED (shorted).

To flip the screen, these need to be reversed. That is, CLOSE SL6 and OPEN CL9.

You can close (short) SL6 by just applying a large solder blob to the pad. You can open (cut) CL9 with a sharp exacto knife.

Thats it, next time you powerup your screen should be flipped!

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dkj1 dkj2 dkj3

Switchable flip screen hack

You can also make this hack switchable if desired. Nintendo also designed into the boardset a place to install a switch. However, I've not been able to locate a SPDT switch that fits. I found the easiest way to make the flip screen switchable is to install a small DIP switch, preferable a 2 position one. I did not have a 2-position one when I took these example photos, so I installed a 4 position one instead and did not use the other two position. (See note further down about safety precaution when using a DIP switch to avoid short circuiting the boardset).

First, make the cut on CL9 as shown above, but do not jumper SL6 (leave it open also). Locate the yellow block adjacent to the SL6/CL9 pads mentioned above. At the end of the block you will see an M on one side and an S on the other side. These 4 nearest pads (2 on each side) will be where the 2-position DIP switch mount (note I used a 4-position switch in this example). Remove the solder from holes that will hold the DIP switch. Solder in the DIP switch.

Caution with this DIP switch configuration it is assumed that only one of the switches will ever be in the ON position, if more than one is place one, it will create a short circuit and could damage your board. Also, if you are using a 4-position or larger DIP switch as I have in this example, make sure all of the other postions are also switched OFF.

The bottom two switches control whether the screen is flipped or not. Basically these two switches form a SPDT switch. With SW1 ON, and SW2 OFF, the screen will be in its normal state. With SW1 OFF, and SW1 ON, the screen will be in a flipped state.

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larger view

Strap and switch location
cut CL9 trace

Normal Screen Setting

Flipped Screen Setting