Controller functions are mapped to the computer keyboard; an extended keyboard is required to access both left and right Intellivision controllers. With Macintosh, USB game controllers could be used indirectly with a joystick to keyboard mapper utility. For PC, Intellivision Productions promoted the Gravis GamePad Pro game controller (game port version). The MS-DOS emulator, directly accessible on the CD-ROM, also supported original Intellivision controllers through the INTV2PC Hand Controller Interface. INTV2PC is a parallel port adapter that accepts original Intellivision hand controllers. This feature although not promoted is documented in the "INTVPC" files on the CD-ROM. Modern intellivision emulators and USB controller adapters have since become available, compatible with the Intellivision Lives rom image files.