Sega Mega Drive Cartridges from Japan

Sega Mega Drive Cartridges from Japan.  The Mega Drive runs games housed in plastic cartridges uniquely shaped to fit the system. Though the technology exists to run Sega Master System games, the Power Base Converter is required to convert between the differing pin connections and slot sizes.

Official Mega Drive cartridges are generally smaller than their Master System/Mark III counterparts, with rounded edges and, in the case of “western” systems, bigger labels layered over the top and front of the cartridge. Region locking exists, albeit in a selection of rather crude forms – the TradeMark Security System, which is missing in many early Mega Drive systems, through software checks implemented manually by developers (which did not begin to feature in new releases until 1993), and differences in cartridge shape. Region locking is easily circumvented through the use of adapters – troubles only arise when dealing with 50Hz/60Hz differences between NTSC and PAL systems, leading some games to run too slowly while others, too fast.

As with the Master System, Sega-manufactured Japanese, Korean and Asian cartridges are shaped differently to those seen in North America, South America, Europe and Oceania, however the differences largely concern the aesthetics – “Eastern” Japanese-style cartridges opting for a more rounded approach with ridges, while “Western” cartridges being more angular and simplistic. Unlike the Master System, the Mega Drive has end-labels for easier reading and storage in western regions.

Pin layout is the same between the two types, however the base of the cartridge determines whether it can be safely inserted into the system – two extra pieces of plastic prevent Japanese cartridges from being inserted in western systems – these can be removed with modification, or as mentioned above, circumvented with adapters. This extra plastic is not present in systems such as the Genesis 3 and Sega 32X, nor does it exist in Japanese Mega Drives.

One interesting feature of Japanese cartridges is a inclusion of a cartridge “lock”, which prevents the cartridge from being removed when the system turns on. A plastic piece from the system is slid across to a gap on the left hand side of a Japanese cartridge, securing it in place when the power switch is moved (similar tricks can be found in Super Nintendo consoles and the TurboGrafx-16). This locking mechanism is only present in Japanese Model 1 Mega Drives and is absent in all western models – the vast majority of western cartridges lack the gap required for cartridge locking, with exceptions being the likes of “special” cartridges, e.g. Sonic & Knuckles.