SM1
SM1 is the name of the 64kB M1 ROM containing the default sound driver embedded in some NeoGeo MVS systems. It allows testing of the audio without having a cartridge inserted.
Dump name: SM1.SM1 in BIOS sets. Signature:
Ver 1.5b by Mr.Pac h Ber.02/01/08
Same pinout as 27C1000A.