NEC CMOS-4(?) gate array. Model 65006 in a QFP64 package
OKI M6295 ROM Banking chip used in many NMK arcade game PCBs (also in DonPachi and Power Instinct)
It supports up to 2 OKIs.
Provides 8 of 6-bit registers, 4 of them used to store 4 different Bank values for each OKI.
The actual bank value used each time is selected by OKI_A8-9 address bits when addressing ROM sample table (OKI_A10-17 == 0), or by OKI_A16-17 bits otherwise.
SVG file could be overlapped on die image from: https://siliconpr0n.org/archive/doku.php?id=furrtek:nmk:112
Huge thanks to: