NES 2.0 Mapper 600
NES 2.0 Mapper 600 denotes UM6578-based plug-and-play consoles from Advance Bright Limited (ABL) that extend the addressable PRG-ROM from 1 to 2 MiB by switching A20 for the entire address range via $4016 bit 1. Used by Air Blaster 14-in-1. There also is an additional sound chip of an unknown type whose only hardware interface is that writing to bits 2-7 of $4026 starts the sound effect of the written number.