Back in 2009 or so, MAME developer Phil Bennett put aside a driver for the Fairlight CMI IIx he was working on, and never submitted it for inclusion in MAME. After a handful of went by, I offered to update it through the fairly massive number of core API revisions that MAME had undergone in the intervening time.
Unfortunately, either the backup version of the driver was earlier than what was remembered, or my update to the driver mangled things in some way: While the CMI system software has been able to run for ages, the music keyboard module wouldn't make any noise, and any Page R sequences produced little other than short blips.
After spending the past couple of days poring over the schematics for the CMI-01A channel card, I'm happy to say that it's now working well enough to play intelligible music and samples.
The secondary keyboard is currently not implemented, nor is the Analog Card (used for sampling), the MIDI card emulation has some fault that prevents revision 1.2 of the system software from booting, and emulation of the Curtis SSM2045 filter is completely missing so the samples are pretty rough around the edges - but it plays.
Lastly, the reason why I keep inadvertently typing 'P' into the command line at the top of the screen is because I kept having to pause MAME, bring up the file selector, and mount different floppies, as the full sample set for the Page R sequence that I load in this video is split across about 6 different disks.
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