For the development system, the ROM on the game cartridge is replaced by RAM on the development board; in this chapter, we refer to it as "Virtual ROM". This allows the game developer to load the game program into memory, control its execution, and observe the effects of modifying the game to debug without having to rebuild from source.
The development board plugs into the GIO bus of the workstation. Audio and video output connections are provided. Communication facilities between the workstation (referred to as the host in the rest of this chapter) and the development board (called the target) are via the RAM devices that emulate the cartridge ROM and several registers provided for handshaking and synchronization.