A Vectrex controller (modified) is a controller from another console which has been adapted to work on the Vectrex. This is a dedicated controller which no longer functions for the system which it was originally intended for and now only functions for use on a Vectrex. This differs from that of an unmodified controller that utilizes an adapter device to function on a Vectrex. In this setup, the adapter converts the button signals to appropriate ones to operate with the Vectrex while still allowing the controller to be used on the system it was originally intended for.
Analog Versus Digital Controls
Thus far, the majority of modified controller has utilized digital controls rather than analog controls. This control scheme is compatible with most games released both originally and more recently (as in homebrews); however, games such as Hyperchase, XMas Cart 2014, or Spike's Water Balloons Analog require analog controls and cannot be used with a digital controller. Any controller modified using a Super Nintendo or Sega Genesis controller will use a digital control scheme; however, ones modified from a PlayStation might utilize the analog design of the controller's joystick for analog controls. If the directional pad (D-pad) is used instead, then only digital controls are supported.
Homebrew Modified Controllers
While Sega Genesis/MegaDrive controllers tend to be the most popular controller to modify, controllers from many systems have been modified for use with the Vectrex. Among them are the original PlayStation, Playstation 2, Atari 2600, TRS-80, Super Nintendo, Sega Saturn, NeoGeo/NGX, Xbox, and various wired and wireless controllers intended for gaming on home computers.
Recycled Gamer offers some of the most well known modified controllers. Chuck Van Pelt of Recycled Gamer offered his modified controllers on eBay, at conventions and through his website. His two most popular controllers were modified from original official licensed Super Nintendo and Sega Genesis (3 button) controllers. Earlier versions of these controllers used wires to modify them, but later versions used replacement PCBs of his own design to expedite production. He also did created some low production number modifications and one-off prototype controllers which were deemed too labor intensive, cost prohibitive and/or unpopular to produce on a larger scale. His prototype controllers used Sega Saturn Arcade Sticks, Sega Genesis Mega Sticks, and PlayStation Analog Sticks, among others.
A converted John Dondzila Genesis controller.
John Donzila also offered several modified Sega Genesis controllers, though several brands and versions were used in his modification, such as the Innovation six button and official licensed controllers. Madtronix has also sold a modified controller, which is listed on his site as a "cheap gamepad" and also utilized a third-party six button controller.
Recently, there has emerged a PCB design by Vector gaming forum user SiLic0ne t0aD, which replaces the one used in a NeoGeoX Arcade Controller. The PCB can be ordered from OSHPark and is a do-it-yourself solution. Also, homebrewer Keith Horn modified an Atari 2600 Paddle Controller to use with Hyperchase, which would later be dubbed the Vecdrive controller, having a switch to change gears.
Video of the Vecdrive controller