MAME Cabinet in 4 key steps

Step 2 VGA to the Arcade Monitor hookup

When you're converting an Arcade Cabinet into a MAME cabinet, there's roughly three options you can use for the display:

• Use a PC monitor ; that's the easiest solution but also IMHO the worth solution because you're going to loose all the look & feel of an original Arcade display.
• Use a TV with the S-Video or HDTV out of the video card ; that's a compromise between the above and below options.
• Use an original Arcade Monitor ; what's more authentic than the original ? IMHO that's the method you have to use and none others. And that's what I'm going to outline in detail now.

In an Arcade Cabinet, video signals goes from the arcade system board (PCB) to the monitor through a harness. This harness is commonly made of 5 colored wires:

• Red wire: red signal (rgb)
• Green Wire: green signal (rgb)
• Blue wire: blue signal (rgb)
• Black wire: ground
• White wire: horizontal synchronization (H)

Harness' can vary from one Arcade monitor model to another, but there should be a wiring diagram labeled on your arcade monitor chassis showing what wire is used for what signal. In any case you should be able to find this information in your Arcade Monitor User's Manual.

In order to connect an Arcade monitor to a VGA card, you have to solder individually the 5 harness' wires to a 15 pins VGA male connector. (mini D15) using the attached diagram.

Please also note, one some arcade monitors there's also a vertical synchronyzation wire (V) ; if there's such a wire, simply solder it together with the horizontal synchronization wire (H). That concludes the wiring part.

However even after the harness is properly rewired, the display will still not work because real Arcade monitors works with a 15 or 25 Khz refreshing rates and computer video cards displays at rates over 31 Mhz (depending on the video card model). To go around this problem, you have basically two options. Beware that plugging an Arcade monitor to a regular computer video card without the use of iether options below can irreversibly damage the monitor !

• Set the frequency of your existing video card to 15 khz with the help of a special software called a Tweaker. This can be done directly through front-ends for MAME such as ArcadeOS or AdvanceMAME for examples. This option as one major drawback, besides its initial setup and tuning which may be tricky: you have to delay the powering of your monitor, in order to wait for the Operating System and the Tweaker to load first.
• Get the ArcadeVGA video card from Ultimarc. This card is based on a regular ATI Radeon but was modified to work natively at a 15 khz refreshing rate. This option, even though it can be pricey (although at the price of a medium range video card), is by far the easiest because it is literally plug & play.

In all the four critical steps I'm describing here, I consider this one to be the most tricky because of the many parameters that are involved at the same time (wiring of the VGA harness, software to setup, monitor tuning etc.) and thus may be difficult to troubleshot all at once.