Early version of Tehkan World Cup

 Tehkan World Cup  Comments Off on Early version of Tehkan World Cup
Jul 292017
 

I’ve been working on trying to fix an original Tehkan World Cup PCB for quite some time, but not making much headway.

What has been really interesting about this repair is that I have discovered that the majority of the roms on the main CPU board were not known in Mame. Sometimes this is just a case of the rom data being corrupt, but I have managed to run the game data in Mame, and it looked fine, so that ruled that possibility out. What I noticed is that it was different to the version I had previously seen. I compared the two side by side so you can see the differences yourself. You’ll notice that the logo looks different and there is no world cup image in my version:

YouTube Comparison

With the help of another collector I submitted the rom data to the Mame team and it turns out that this is an early version of the game and even has a different way of handling the dip switches.

The information that was added to Mame can be seen at the page below:

Mame Tehkan World Cup Info

I also submitted some pictures of the CPU and video board to the Mame team so they were aware of any markings on the board which might provide some more information:

Tehkan WC CPU Board

Tehkan WC Video Board

Tehkan World Cup Pinout

 Tehkan World Cup  Comments Off on Tehkan World Cup Pinout
Jun 032017
 

I’ve started to take a look at an original Tehkan World Cup PCB in order to start to get the electronics side of things done before I move onto the conversion of my empty Atari Dunk Shot cabinet to a Tehkan World Cup cabinet.

The PCB itself was filty when I dug it out of the loft so I decided to give it a good clean. Whilst I was waiting for it to dry I started having a look on the Internet for pinouts so I could wire up a Jamma adaptor.

I came across two possible pinouts. One on Andysarcade.net and the other on Powerstrike.net.

Andy stated on his website that the powerstrike pinout was incorrect. I found this was partly true, as the pinout was correct but the wrong way round e.g. A and 1 was really V and 18 according to Andy’s list. In fact I believe they both use the wrong labelling for the connections because the PCB is labelled B1-B18 on both connectors on the parts side, and I suspect that the solder side is classed as A1-A18, so that’s what I’ve used with my attempt of the pinout. The connectors are also labelled J1 and J2 on an original PCB so I’ve also made that clear on my diagram. Hopefully it makes more sense?

Tehkan World Cup Pinout

Tehkan World Cup Pinout

I’ve yet to confirm my wiring is 100% but I’m fairly convinced it is. I will give an update on this when I’ve done my Jamma harness. I have used the Tehkan World Cup manual I have on my site which can be found here. The only problem with the manual is that it is not the most readable as it looks like it has been photocopied over and over, but it seems to be the only one on the Internet!

Atari Pokey Tester

 Technical Info  Comments Off on Atari Pokey Tester
May 012017
 

I wanted to see if it was possible to test Atari Pokey chips using an Atari 7800 console. Here’s what happened:

Atari Pokey Tester

I would like to say a massive thanks to Michael “RevEng” Saarna, the author of Atari 7800 Basic, who helped to get the code working for the tester, and members of AtariAge forum who made suggestions on how I could move the project forward.

The program is available to download below should you wish to try this out:

Atari Pokey Tester (34 downloads)

Vs. RBI Baseball Repair and Test

 Nintendo Vs  Comments Off on Vs. RBI Baseball Repair and Test
Apr 222017
 

I received a broken RBI Baseball daughterboard from a member of the Klov forum in the US. The cool thing about having this daughterboard is that it can also be used to play Vs. Super Sky Kid on the Nintendo Red Tent, so I was very pleased to have it in my collection.

Here is how I got on with the board:

VSRBI