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Arcade
Emulation The box of goodies from Ultimarc arrived last week, and there was much rejoicing. I fully recognize that getting excited about a couple of circuit boards and a bunch of wire is completely geeky. But hey, you're the one here reading about it so hopefully I can assume that at some level we're connecting on how cool this is:
What you're looking at here is the necessary equipment to connect the arcade controls on the Neo cab to a standard PC keyboard port, and the arcade monitor to the PC. The first board is called a J-PAC; it is designed to allow swift connection between the parts inside an arcade cabinet and a PC. It has 28 inputs for buttons and joysticks. When buttons are pressed, the J-PAC converts the signal into keystrokes and sends them to the computer as if you had pressed a key on your keyboard. It also takes the standard 1-Volt VGA signal and amplfies it to the 5-volts required by the arcade monitor.
Here you can see how the J-PAC gets connected. On the bottom-right is the VGA cable from the video card. The purple connector is a standard keyboard plugged into the J-PAC. The standard keyboard gets passed through to the keyboard output on the left along with any keyboard commands generated by button presses. At the top, that colorful collection of wires is a standard JAMMA harness. JAMMA stands for Japanese Arcade Machine Manufacturers Association and is essentially a standard connector designed to make it easy for arcade operators to switch out arcade boards quickly and easily. The edge connector on the JAMMA harness slides onto the fingerboard portion of the J-PAC. The other board that arrived in the package is the ArcadeVGA video card. This video card is designed to operate low-frequency monitors like the one in the Neo cab. Most VGA cards output a 31kHz signal. Old arcade monitors, which sync at a much lower 15kHz, can't display a VGA signal. Not only does the ArcadeVGA output a 15kHz signal, but it is pre-programmed with most of the necessary custom resolutions required by older arcade games (for example 400x256, used by Mortal Kombat).
The ArcadeVGA also has some video modes that allow standard windows VGA resolutions (640x480, 800x600 and 1024x768) to be viewable on the Arcade monitor by employing interlaced video. While it is possible to use a program like PowerStrip to create custom video resolutions on other cards, it only works with a few cards (such as the nVidia GeForce) which are often more expensive than the ArcadeVGA. Its a bargain even before you factor in how much time and headache you save. For example, the timings on the ArcadeVGA card are already set up perfectly so that when you switch resolutions you don't have to adjust the horizontal and vertical size/position of your monitor to be centered on the screen. Just center it once and forget about it. Okay enough about the video card. It's time to hook all this stuff up and make sure it works:
Here you can see one of my co-workers re-living his youth in a game of Gyruss. At this point I just wanted to test out the J-PAC and ArcadeVGA and get a taste of the gaming goodness that was to come. Little did I know that this simple game would soon spawn an insane high-score competition in the office. The next step was to build up a PC that could be mounted onto the piece of plywood you see in the above photo. The goal here was to make the PC as "swappable" as any other JAMMA-compatible arcade board. Mounting the PC to a board also helps to make the machine a bit more rugged (no loose PC parts rolling around inside the cab when you move it).
Here you can see the J-PAC on the left. Next to it is a bracket securing a 120 Gigabyte hard drive (I plan on loading up the old laserdisc games such as Dragon's Lair using Daphne). To the right is the PC motherboard with a 1.6 GigaHertz Athlon processor, the ArcadeVGA board, sound card and ethernet card. I pretty much built this machine from spare parts; if I were to build one from scratch I might consider one of the new nForce motherboards in the microATX form factor, such as Shuttle's MN31N. Not only is it a whole lot smaller, but it has on-board audio and network ports, eliminating the need for those 2 cards.
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