ctr wrote:"219 custom" is the C219 chip (the C stands for custom). It is used in both the NA-1 and NA-2 boards. The C219 handles a few different tasks, but it has a sound chip built in, which is based on the C140 with some differences. The main differences are that samples are stored in RAM instead of ROM and the polyphony is 16 instead of 24.
There is also a noise generator (used in this game and X-Day 2) and support for the same mulaw sound format as the C352 (used in Knuckle Heads), though this is missing from MAME and VGMPlay, so I suggest you use QuattroPlay instead.
The NA-1 and NA-2 versions of Emeraldia are practically identical, from what I know.
I have read that the C219 sound chip was only used in the game Namco Classics Vol.1, which is a collection of four arcade games that were originally released in the 1980s. The other games in the Namco NA-1 system (Fighter & Attacker, Emeraldia, and Rompers) all use the C140 sound chip.