FreeIntv with Onscreen Interactive Keypad Overlays

FreeIntv is a libretro emulation core for the Mattel Intellivision designed to be compatible with joypads from the SNES era forward even if they originally required a number pad.

Current Version: Enhanced with onscreen interactive keypad overlays for Android, Windows, and Linux (November 24, 2025)

Authors & Contributors

FreeIntv was created by David Richardson. The PSG and STIC emulation was made closer to hardware and optimized by Oscar Toledo G. (nanochess), who also added save states.

The Intellivoice code has been contributed by Joe Zbiciak (author of jzintv), and adapted by Oscar Toledo G. (nanochess)

Onscreen Overlay Enhancement: Onscreen interactive keypad overlays with touchscreen (Android) and mouse (Windows/Linux) support (November 2025) by Jason Carr

Installation

Step 1: Install FreeIntv Core

• Place the compiled core file for your platform into RetroArch's cores/ directory:
  • Windows: FreeIntv_libretro.dll
  • Linux: FreeIntv_libretro.so
  • macOS: FreeIntv_libretro.dylib

Step 2: Install the Core Info File

• Copy FreeIntv_libretro.info to RetroArch's info/ directory
• ⚠️ The filename must match the core filename exactly (excluding the file extension)

Step 3: Add BIOS Files

• Place the two required Intellivision BIOS files in RetroArch's system/ directory:
  • exec.bin (Executive ROM)
  • grom.bin (Graphics ROM)

Step 4: Launch Games

• Load an Intellivision ROM through RetroArch using the FreeIntv core

Enabling Onscreen Interactive Overlays

The FreeIntv core features onscreen interactive keypad overlays that display custom controller graphics directly on screen, allowing touch or mouse input.

To Enable the Feature:

1. Launch a game using the FreeIntv core
2. Open the Quick Menu (usually Hotkey + X on your controller, or through RetroArch's menu)
3. Navigate to: Options → Core Options
4. Enable the overlay feature
5. Close the menu (RESTART to take effect)
6. Revert to fullscreen follow same instructions but disable core option, and restart to take effect.

The onscreen interactive overlay will now be active, allowing you to touch or click buttons directly on screen!

License

The FreeIntv core is licensed under GPLv2+. More information at https://github.com/libretro/FreeIntv/blob/master/LICENSE

BIOS

FreeIntv requires two Intellivision BIOS files to be placed in the libretro 'system' folder:

Function	Filename*	MD5 Hash
Executive ROM	exec.bin	62e761035cb657903761800f4437b8af
Graphics ROM	grom.bin	0cd5946c6473e42e8e4c2137785e427f

• BIOS filenames are case-sensitive

Entertainment Computer System

FreeIntv does not currently support Entertainment Computer System (ECS) functionality. Contributions to the code are welcome!

Game Overlays

Mattel Intellivision games were often meant to be played with game-specific cards overlaid on the numeric keypad. These overlays convey information which can be very useful in gameplay. Images of a limited selection of Intellivision titles are available at: http://www.intellivisionlives.com/bluesky/games/instructions.shtml

Overlay Setup Instructions

To use custom game overlays with the touchscreen UI on Android or mouse input on Windows/Linux:

Folder Location:

• Create a folder named freeintv_overlays in the same directory where you keep your BIOS files (exec.bin and grom.bin)
• Typically: RetroArch/system/freeintv_overlays/

Overlay Image Specifications:

• Dimensions: 370×600 pixels
• Format: PNG image (any color depth)
• Naming: Match your ROM filename exactly (case-insensitive on most systems)
  • Example: If your ROM is astrosmash.bin, name the overlay astrosmash.png
  • Example: If your ROM is nightstalker.rom, name the overlay nightstalker.png

Example Folder Structure:

system/
├── exec.bin
├── grom.bin
└── freeintv_overlays/
    ├── astrosmash.png
    ├── nightstalker.png
    ├── weekendwar.png
    └── (additional game overlays...)

Usage:

1. When a game launches, FreeIntv automatically looks for a matching overlay image in the freeintv_overlays folder
2. If found, the overlay is displayed on the keypad area (right side of screen, or left if swapped)
3. Touch or click directly on the overlay buttons to send input to the game

Touch and Mouse Input

• On Android, touch the onscreen keypad overlay buttons to send input
• On Windows and Linux, use the mouse to click on the overlay buttons. Mouse clicks are mapped to input events, enabling full overlay functionality.

Controls

Traditional Gamepad Controls

• Controller Swap - Some Intellivision games expect the left controller to be player one, others expect the right controller. This isn't a problem if you have two controllers (and don't mind juggling them) but users with only one controller or using a portable setup would be effectively locked out of some games. Controller Swap swaps the two controller interfaces so that the player does not have to physically swap controllers.

Onscreen Interactive Overlay Controls (New)

• Onscreen Keypad - Touch (Android) or click (Windows/Linux) any of the 12 buttons (1-9, *, 0, #) directly on the overlay to input commands
• Custom Overlays - ROM-specific overlay images display game-specific button layouts and instructions
• Visual Feedback - Button presses show highlighting on keypad buttons

RetroPad Mapping

RetroPad	FreeIntv Function
D-Pad	8-way movement
Left Analog Stick	16-way disc
Right Analog Stick	8-way keypad
L3	Keypad 0
R3	Keypad 5
L2	Keypad Clear
R2	Keypad Enter
A	Left Action Button
B	Right Action Button
Y	Top Action Button
X	Use the Last Selected Intellivision Keypad Button. In Astrosmash, for example, you can leave "3" selected to enable instant access to hyperspace.
L/R	Activate the Mini-Keypad
Start	Pause Game
Select	Controller Swap