Same Plunger, New Game: How a 1986 Gottlieb Raven Became G.I. Joe: Operation Raven

On October 3, 2026, a 1986 Gottlieb Raven stood in a garage with its coin door hanging off its wiring, no apron, no caps on its pop bumpers, and new G.I. Joe art being test-fitted piece by piece. The machine belongs to Craig Monyhan, the homebrew builder behind Steamboat Willie. Craig had been turning his Raven into a G.I. Joe game for a show, and it wasn't finished: coils had burned their fuses, and some holes in the playfield were too small for the targets to pass through.

Nine days later, it played a brand-new game. That week it went to Pinball Expo. Today it lives at Craig's.

"G.I. Joe started as a 1986 Raven that wasn't finished. Nine days later it plays a brand-new game, and the original Raven is still one minute away."

Valère, founder, Pinballs Store

Here is the whole story: the machine, the board inside it, what we built in those nine days, and why none of it contradicts what we've written about leaving the games you love alone.

The builder who handed us a Raven

If you were at Pinball Expo 2025, you may have met Craig's other machine. Steamboat Willie is a homebrew whose cabinet he built from a parted-out 1960s machine, with art drawn from the public-domain Steamboat Willie cartoon. He first showed it in 2020, then rebuilt it as Steamboat Willie 2.0 in 2025 with a ramp, an upper playfield and three motorized toys. Craig designed the game, directed its art and wrote its control software himself. When a builder like that hands you his Raven, you take it seriously.

A forty-year-old brain

The Raven is a Gottlieb System 80B game from 1986. Like every System 80, its brain is a CPU board built around a 6502 processor, three 6532 RIOT chips, a 5101 memory chip and the game's PROMs.

Forty years on, those boards fail in ways every owner knows. The battery that keeps your settings and high scores leaks, and the electrolyte eats the copper. The RIOTs and other original chips are no longer made, so every repair means hunting second-hand parts. And Gottlieb chained the ground from board to board through the harness, so a few tired connectors are enough for faults no schematic predicts.

Rebuild the board, don't patch it

The Raven now runs on a GottFA80_Plus, the all-in-one board Ralf Thelen designed for his open LISY project (lisy.dev), with our FPGA module, the Smart FA, plugged on top. On a System 80B it takes the place of the original CPU board and driver board; the original power supply stays. There is no battery: settings and high scores are saved in an EEPROM.

Credit where it's due: the GottFA80 design, including the FPGA recreation of the System 80 board, is Ralf's work, shared openly. Thank you, Ralf. We build on it, add our own blocks, and test every board before it ships.

The Smart FA also carries an ESP32 Wi-Fi chip. It runs FA·CONTROL, our free Wi-Fi service tool: open a browser on your phone or laptop to test every lamp, coil and switch, read the game's memory, play sounds, drive the displays and run a self-test. It speaks the LISY protocol.

"Patching a forty-year-old board buys you time. Rebuilding it in an FPGA buys you the next forty years: same game, same code, none of the old failures."

Valère

Inside the FPGA

An FPGA is a chip whose circuits are written as code. It doesn't run a program that imitates a 1986 processor: it becomes the processor, gate by gate. That is the difference between our boards and software emulation.

Ours is an AMD Xilinx Spartan-6 LX9. Inside it, the Raven's CPU board is rebuilt chip by chip: a 6502 core; the three 6532 RIOTs that read the switches and drive the displays, coils, lamps and sound commands; the 5101 memory, now in on-chip RAM; and the two game PROMs, copied from the module's flash into on-chip memory at every power-up. The game code is the original. Load the stock Raven image and the FPGA runs Raven's own program, unchanged.

For the Expo, Valère wanted people to see this, so we drew the real map of the chip, taken from the placed design of the exact image running in the Raven. It uses 3,341 of the chip's 5,720 lookup tables (its basic logic cells), or 58 %:

• 1,134 recreate the 1986 chips;
• 637 are Ralf's GottFA platform: battery-free memory, game selection by DIP switch, a boot that keeps the coils safe, true free play;
• 1,364 are Pinballs Store blocks;
• 206, plus 19 blocks of on-chip memory, are the seven homebrew blocks.

What our own blocks do, in plain words:

• A game library in flash. At power-up the FPGA loads the game from the module's own flash memory, which holds a coin-play and a free-play copy of each game. No SD card.
• A link to the ESP32. One wire tells the Wi-Fi chip every sound command, which game is running and whether the CPU is alive. Another brings the ESP32's sound samples back, to be mixed and sent to the amplifier.
• A live memory mirror. A shadow copy of the game's working memory goes to the ESP32 every 0.4 seconds while the game plays. That is how the board can follow the display and the game.
• The service bridge. What FA·CONTROL uses to drive lamps, coils, switches and displays from your browser, with the game's CPU held.
• For homebrew: a filter that stops chosen sound commands before they reach the 1986 sound board, so the ESP32 can play something else; a port that lets new code call up to 256 new sounds; a mailbox that lets a web page talk to the game while it runs; and code windows plus a 32 KB ROM extension that give new code room beside the original. Raven's program is 10 KB; the G.I. Joe ROM is 48 KB. All of this switches on only when the loaded game carries a homebrew marker. A stock game runs exactly as stock.

The FPGA's own configuration is updated over USB through the ESP32, and every page is read back and checked before the chip restarts.

A new game, without touching the old one

If you read this blog, you know where we stand. In "Don't Touch the Plunger" we wrote about altered rules and modified scoring: "we'd rather lose a sale than build it." So why build a whole new game?

Because this isn't Raven with its rules bent. G.I. Joe: Operation Raven is a separate game, made for Craig's own machine, with his full agreement. Raven itself is untouched: its original ROM image stays in the board's game library, and switching back takes about a minute from the board's web page. Same plunger, same steel ball, same flippers. It isn't for sale, either: it's a one-off, non-commercial fan build, and a demo of what our boards can do.

And the new screen? It sits in the apron, where an instruction card goes, and it does an instruction card's job.

Nine days, mission by mission

Day one went into reading the Raven's program and getting our tools and emulator running on it. On day two, October 4, the head was back on the cabinet, our board was wired in, and the display lit up with a new title: INCOMING TRANSMISSION, then G.I. JOE stamped letter by letter. By that night you could pick a mission, and a friend could send commands from a tablet: the game answered with a voice 0.06 seconds after the tap.

Then, day after day:

• Five missions, chosen in attract with the flipper buttons. MISSION is Raven's own rules with G.I. Joe texts. COBRA HUNT raises a sniper every ball. In VETERAN, a sniper left standing for 30 seconds opens fire, and your flippers die every 10 seconds until you hit one. BLITZ 3 MIN gives each player three minutes on the clock; a lost ball comes back, minus 30 seconds.
• Cobra's four snipers have names now, after their playfield panels: DESTRO, STORM SHADOW, BARONESS and COBRA COMMANDER, on the display and by voice.
• GAME MASTER: a friend with a phone sends AIR STRIKE, DOUBLE SCORE or SNIPER DOWN, or curses like FLIPPER JAM and LIGHTS OUT. In TARGET LOCK they tap a target on a drawing of the playfield: every insert goes dark except that one, which blinks, and you have 15 to 60 seconds to hit it.
• New sound. The 1986 sound board is retired. The FPGA holds back the game's sound commands, and the ESP32 plays its own files, plus the new voices the new code calls for.
• An apron screen: a Raspberry Pi and a 3.5-inch screen, styled like Gottlieb's black instruction cards. It follows the game: how to pick a mission, the rules of the one you're playing, the sniper to hit, the TARGET LOCK countdown.
• Little touches: the knocker fires five times as G.I. JOE lands in the title, the inserts run a light show in attract, free-play credits read HB for homebrew, and a game can end with a Gottlieb-style MATCH that awards a prize, on free play only.

When the code windows were full to the last byte, we added the 32 KB extension to the FPGA. Every build went through our emulator, which runs the Raven about 80 times faster than real time, before it went into the machine. The last release passed 2,494 checks out of 2,494, and coil pulses were checked against the original game's ranges. The final fix went in on October 12, two days before the show.

Booth 321

From October 14 to 17, at Pinball Expo in Schaumburg, our very first show, the machine stood on Booth 321 as a technology demo anyone could play, and more than 500 people played it. The show T-shirts say who made it: Craig Monyhan & Pinballs Store.

Back home, and version 2

After the show, the Raven went home with Craig. And we're not done with it: version 2 of Operation Raven is already in the works.

What's next

Everything we built for Operation Raven that isn't G.I. Joe went into a toolbox we can reuse for other Gottlieb games. And it isn't just for us: one day, you'll be able to use it too, and make your own homebrew for your own Gottlieb, without writing code. No dates and no promises, but Operation Raven won't be the last.

We've also opened a place to talk about all of this: the Pinballs Store Community at forum.pinballs.store. Log in with the account you already have on pinballs.store or us.pinballs.store.

Your turn

Questions about Operation Raven, the FPGA or homebrew? Ask in the forum's Homebrew & ROMs category at forum.pinballs.store. Is your Gottlieb, Williams or Bally down? Tell us your machine and the exact symptom on pinballs.store (Europe) or us.pinballs.store (United States): we'll tell you which board you need, or whether you need one at all.

Thanks, Craig. Thank you, Ralf.

G.I. Joe is a trademark of Hasbro. This is a one-off, non-commercial fan build, not affiliated with or endorsed by Hasbro.