Released in 1991, the Multi Game Doctor 2 by Bung is one of the most versatile copiers there are. The MGD2 has can be used with 7 different systems including the SNES, Genesis, NEO-GEO, PC-Engine, Super Graphics, Game Gear, and Game Boy. The main unit has an LCD screen and three buttons which control the copier's functions. The unit is compatible with gold finger codes, DSP games and has built in 256K of SRAM. It has support for two languages (Chinese and English) and the contents of the memory are maintained when the console's power is turned off. The Neo Geo I/O can playback games up to 136M, the I/O utilizes 4x32M Doctor cards, and one 8M SRAM (thanks Kyuusaku). Games can be backed up on 720K, 800K, 1.2MB, 1.44MB and 1.6MB formats. It had a backup board (for making the initial backups), but it did not come in any protective case, just the bare board, so very few now survive, they are now VERY, VERY rare. The dealer would usualy attach whatever cart conectors the buyer/user needed.
Comment 1: Just like Super Twin Star, except it has a much smaller LCD display, and its RAM cart uses tiny lithium battery, and about the size of a Game Boy cartridge. can have a max of 32M memory, but right now only offers a max of 8M RAM cart. (Super twin star uses a regular AA or AAA battery for its RAM cart, but the lithium battery in Multi Game Doctor 2 RAM carts lasts only a month) right now, have interface for Mega Drive, Super Famicom, PC-Engine, NEC Super Grafx, Game Boy, and Game Gear.
The Multi-Game Doctor II which supports every known system from back then (including Neo-Geo) did cost $650