Wow! I'm finally starting the log on my cocktail project. I haven't even finished my upright Mame machine yet, but I've taken on the task of converting a Donkey Kong cocktail machine into a Mame machine. Before any of you purists decide to send me hate mail for "destroying" a Donkey Kong machine, please read on. This first entry will be a long one since I have some catching up to do!
I bought my first Donkey Kong cocktail machine from a local thrift shop for $25. Once I got over the shock of actually seeing the machine in the first place I plugged it in to see if it worked. I didn't see a picture, but it sounded like the game started up, so I looked around (while still in the thrift shop) and noticed that one of the potentiometers on the monitor had a broken leg. Ignoring the hazard-warning stickers, I shorted the broken leg with a key and saw Donkey Kong! I rounded up a worker and told him that I wanted to buy the machine, but would have to come back with a truck. While I'm talking, there were a bunch of little kids messing with the machine, which king of freaked me out a bit, but they didn't seem to hurt anything. I was really worried that they would open the top and start pulling on wires.
A couple of months after buying the first Donkey Kong machine, I was back in the same thrift shop again. I could hardly believe that there was another one of the same exact machines there. This time they wanted $30, and I bought the machine up without even trying it. Unfortunately this machine had a multitude of problems: The game board has a sprite problem; The power supply was blown; The monitor didn't seem to work properly. After a bit of fiddling, I was able to get the monitor adjusted properly, though it needs a cap-kit still (I have the kit, just haven't installed it). The saving grace is that the table-top was in much better shape than my first machine. The stickers were all in pristine condition!
Once I combined the best parts from each machine to make one in decent shape, I set the second machine aside for a couple of years. Recently I've decided that it was time to try and fix the problems the second machine had. The first thing I tried to do was install a new switching power supply in the new machine. Unfortunately that didn't work. For some reason, I couldn't get the switcher (Slang I've picked up from reading rec.games.arcade.collecting) to power up the Donkey Kong board. After some investigation I found out that my board-set was a very early version, which was not originally Donkey Kong at all, but Radar Scope. This was indicated by a TKG-2 sticker over TRS-2. It turns out that the Radar Scope boards require a power supply that can provide 2-3 amps on the -5v line, where the switcher only provids 1 amp. I searched far and wide for a power supply that would properly run Donkey Kong and came up empty.
My next thought was to buy a later board set which didn't require the higher amperage. After thinking about it for a bit, I realized that it probably wouldn't be much more fun to have two Donkey Kong machines around than one anyway, so I looked for Donkey Kong Junior board sets. The board sets are available, but I felt if I wasn't going to restore the second machine to an authentic Donkey Kong, then I might as well put a bunch of games in it VIA Mame. I had already put together a Mame upright (I say "put together" loosely since it really never went far once I got it to a point that I could play the games, but it will some day).
The first obstacle I wanted to address was the display. I've decided to go with installing an NTSC monitor in the Mame cabinet. There are several reasons for this decision:
I was able to bolt the innards of a Commodore 1702 monitor to the original Donkey Kong monitor mounts with very little modification. Actually, I just needed to drill 3 holes in the 1702 monitor's circuit board housing. (first two holes) (third hole) The monitor fit like a glove, here you can see the clearance between the picture tube of the 1702 monitor and the shield from the original Donkey Kong monitor. Since the monitor fit perfectly in the original monitor mounting brackets, there was no problem installing it back in the cabinet.
Next, I had to figure a way to install a computer in the belly of this thing. Unfortunately, there is not a whole lot of room . I'm planning to use a Compaq Deskpro computer because it is low-profile and I already have one on hand. It's a 150mhz Pentium, which should do well for the type of games I want to play (Pac Man, Donkey Kong, Galaga, etc.). I have an ATI All-in-Wonder card that I no longer use for video capture which will provide the NTSC signal. Actually, I did some reading today and found that the S-Video out provides Chroma and Luma signals which the Commodore 1702 monitor conveniently has inputs for! I need to make an adaptor and I should be in business. I'm planning on hacking up the case of the computer and installing the motherboard and hard drive to the right of the monitor and the power supply to the left of the monitor. I'll need to extend some wires on the power supply to do this, not a big deal. My initial measurements show that everything should fit.
I felt that I needed to ensure that the hardware I am planning on using was feasible. I installed DOS on the PC, along with Mame. Unfortunately, Mame did not work when I attempted to run it in DOS with the monitor hooked up. It just locked up. I installed Windows and found that if I went to a DOS box from there that everything worked well. I struggled for a few days trying various solutions for DOS, including Display Doctor and AdvanceMame, but nothing worked other than Windows DOS. I decided that it would be acceptable to boot into Windows and run a DOS prompt to run Mame, but there was a hitch in this plan too. I don't intend to install any pointing device in the machine, so shutting Windows down would be difficult. Thankfully, I found a program called Shutdown, which I can place in a .bat file to close Windows down properly. I had one more obstacle still, the interface for Mame. Taking the lead from just about everyone else running the DOS version of Mame, I tried ArcadeOS. To make a long story short, it doesn't work in a Windows 98 DOS box (at least on my machine). I ended up finding Game Launcher. My initial tests show that this works fine with my setup. I plan on donating some money to the author when I get my machine finished and if the front-end gets the job done. I will also be using an I-Pac keyboard encoder. I did a keyboard hack on my original Mame machine and it worked well, but the I-Pac makes life soooo much easier that I highly recommend it. At any rate, the proof of concept worked well!
