Jump to content
Due to a large amount of spamers, accounts will now have to be approved by the Admins so please be patient. ×
  • 0
IGNORED

Donkey Kong Video Inverter


Kaizen

Question

I have a number of non working Donkey Kong TKG-4 2-Layer PCB's to repair at the moment and after getting one to boot up on my standard (positive video) monitor I realised I needed an adapter to invert the (inverted/negative video) signals so I can check the colours are correct on each board.

I did some research and found this from Mike Arcade: https://www.mikesarcade.com/cgi-bin/store.pl?sku=NININVAMP

I didn't want to wait weeks for one to be shipped here so I started looking for other options.

There's provisions on the PCB to add some components that weren't populated on the board from factory that allows the video signal to be displayed correctly on a standard monitor but I didn't want to go to the effort of modding multiple boards unless they are fully working, I just wanted something that could be connected inline on my Jamma adapter.

The manual shows the video inverter schematic for each colour.

 

GRfVv90.jpg

 

I drew up a layout for it on Vero board first.

The transistors were substituted with 2N3904's.

 

M0oiVZg.jpg

 

The board was then assembled as per the layout.

 

rMuF9WS.jpg?1

 

This is the image without the colour inverter.

 

Ubcu4Rc.jpg

 

This is how it looks with the inverter.

 

SqZcK4G.jpg

 

 

It works perfectly and the gain on each colour is adjustable.

Link to comment
Share on other sites

3 answers to this question

Recommended Posts

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...