Missile Command Jamma Adaptor

 Jamma Adaptors  Comments Off on Missile Command Jamma Adaptor
Nov 302013
 

I’ve made a really basic Missile Command Jamma Adaptor, to make it easier to test the PCB on a supergun, rather than in cabinet itself. I only connected the following Missile Command pins:

A – GND
C – 12v
L – Blue
M – Green

2 – +5
10 – Red
18 – Comp Sync
19 – -5

Please note the above has the +12v on Jamma pin 6 going to Missile Command pin C. Usually the +12v is on pin 20 on Missile Command, but pin C is also +12v, so this is fine

Missile Command Jamma Parts Side

Missile Command Jamma Solder Side

Nintendo Vs PCB Fix – Excite Bike

 Nintendo Vs  Comments Off on Nintendo Vs PCB Fix – Excite Bike
Nov 302013
 

I purchased a Nintendo Vs system PCB back in Feb 2013 from a UKVac forum member knowing that I was likely to recieve my Red Tent Dual System at some point in the year. I bought the PCB having already purchased a couple of PPU’s off eBay, and these boards don’t appear very often in the UK so I was glad to get my hands on it 🙂

The PCB had clearly been used on a Unisystem as it came with Super Mario Bros and a 0004 PPU on one side, but surprisingly had two CPU’s? I decide to put Excite Bike on the other side of the board with a 0003 PPU, and 6x Eproms I had purchased, utilising the existing extra CPU.

Unfortunately the inital attempt was not promising and I ended up with a blue screen on one side of the screen. At least Super Mario Bros was working on the other screen!

Nintendo Vs PCB Problem Part 1

So I took all the Excite Bike eproms off the PCB and read them in a programmer. To my surprise none of the romset matched anything in Mame apart from 2b. The CRC’s were:

1a = e2902b4e
1b = fbc53465
1c = 6ae01102
1d = f58a392e
2a = 001e8e0b
2b = 80be1f50 – this verifies as (excitebk,Vs. Excitebike,mds-eb4.2b)

It looks like I was not alone with this:

http://forum.arcadecontrols.com/index.php?topic=98242.0

This guy had the same roms as me apart from 1b and 2a. So I was unsure what was going on. Having discussed this with John (blkdog7) from John’s Arcade (http://www.johnsarcade.com), he suggested that it might be entirely possible that I had a different revision that is not in MAME

So I decided to back up the roms I had, erase the 2764’s and write new roms back to the chips from Mame.

Unfortunately I got the same blue screen, so I do not think the original roms were at fault. This meant that it must be a CPU, PPU or PCB issue.

So my first option was to swap the CPU’s over as they are interchangeable. Super Mario would have the Excite Bike CPU and Excite Bike would have the Super Mario CPU and this was the result:

Nintendo Vs PCB Problem Part 2

We have a working Excite Bike…..but a faulty CPU….which is easily replaced 🙂

Electrocoin Midi Mr.Do

 Mr.Do  Comments Off on Electrocoin Midi Mr.Do
Nov 162013
 

I got this cabinet back in September from an arcade barn raid in Wales. The Flickr photoset below was some pictures I took when it arrived. As you can tell, it is incredibly dirty!

I have since been doing some testing on it and found:

1) The PCB was faulty (this is now almost fixed)
2) The switched mode power supply was dead (this has been fixed)
3) The MTC9000 monitor was dead (WIP)
4) The Electrocoin to Mr.Do adapter was damaged

Apart from needing a good clean, the control panel overlay also needs replacing as it has been badly fitted. Also the bottom of the cabinet needs tidying up

Electrocoin Midi Power Supply Rebuild

 Mr.Do  Comments Off on Electrocoin Midi Power Supply Rebuild
Nov 062013
 

I checked the power supply in my Mr.Do themed Electrocoin Midi cabinet and found that the isolation transformer was working as expected, but the voltages from the switch mode PSU were dead. So I took it out of the cabinet, replaced the power supply, fitted a new fuse holder and fuses, and tidied up some of the cables and crimps:

Electrocoin Midi Power Supply

The power supply is now ready to go back in the cabinet