MAMEWorld Forums - MAME Artwork: Official - Drag Race tachometer test

I've been working on this one off and on for couple months, but I've gone as far as I can without some help. Atari Drag Race is pretty much impossible to play without the tachometer to indicate when to shift. I found a photo of the tachometer and created a control panel and separate graphics for the needle in each position. I thought it would work but couldn't test it because MAME would not cooperate. Then recently I realized that Sega's Turbo has working tach output and modified my Drag Race files for Turbo and ... Voila! Working tachometer.

Now I need some help from you guys to get this working with Drag Race. From the schematic, I've determined that the tachometer is driven from the same frequency generator that creates the engine sound. The MAME driver has sound, so that signal is definitely being emulated, but I can't seem to get access to it. It uses 6 outputs per tach which allows for 32 distinct speeds. Tach #1 uses the lowest 6 bits of m_misc_flags (~m_misc_flags & 0x0000001f) and tach #2 uses 6 bits in the middle ((~m_misc_flags & 0x001f0000) >> 0x10). I'm not sure if the driver needs to be modified to makes these signals available to the LAY file or if there's some LAY file commands I don't know about that can do it, but either way I could really use some help.

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