Exidy 440 FPGA

Exidy 440 FPGA Board

Over the last few months I have been struggling to get my Exidy Cheyenne cabinet back up and running. It’s a beautiful specimen that’s given me some issues over the years needing a chassis overhaul and some power supply love here and there, but in general it’s been solid. It’s a beast of a cabinet standing well over 6′ tall and weighing 200+ pounds, what’s more it has a unique control panel with an articulating cast iron light-gun rifle making it that much more special.

I put off getting it on wheels to the very end, but given it was time to bring it to bavastudio I figured a complete strip down and clean-up was in order. I also sent out both boards (one Cheyenne one Crossbow) for testing and they came back in good working order, even though only the Cheyenne board was working properly perviously.

Cheyenne PCB with Crossbow Sound Board

Anyway, long story short, after rebuilding the game in bavastudio I couldn’t get either game board to work. While both worked initially, after a short time the Crossbow board was throwing garbage again and both boards were having intermittent audio issues. The Crossbow board kept blowing out the speakers, and thanks to my laziness/stupidity re-wiring a new speaker I shorted out an audio resistor on the Cheyenne board—which was the only one that kinda worked.

Residue from burnt resistor on Cheyenne’s sound board

It was frustrating to say the least. I tried replacing the resistor and testing things, but the sound was still dead, so I had to step away. Luckily I had a diorama to distract me, but I also knew the Exidy 440 boards were notorious for being fragile, much like many of the Williams boards.

Multi-Williams FPGA Board for Joust, Robotron, Defender, Stargate, and more

While I do want to make sure the original boards are intact, I’m not such a purist that I won’t use modern solutions like FPGA substitute boards to avoid constantly repairing problem boards. Sending in boards to be fixed starts to add up if you can’t do the work yourself.

But let’s take a quick step back, what exactly are FPGA boards? FPGA (Field-Programmable Gate Array) boards provide a hardware-based approach to game emulation that provide near-perfect accuracy by replicating the original hardware at a low level. I have FPGA boards for Joust, Robotron, Defender, and Stargate and the difference in gameplay is undetectable. Given FPGA boards use modern hardware they can do more with less: a single board can run multiple games which would be an ideal solution for Cheyenne, given there are a number of light gun games that use the same 440 system:

In 1983, Exidy began creating light gun games, which had not been popular in the arcades since the heyday of electro-mechanical games. Crossbow (1983) was a success, establishing the Exidy 440 hardware system and prompting the release of more light gun games in the same style. The ‘c’ series consisted of Cheyenne, Combat, Crackshot, Clay Pigeon, and Chiller (1986).

As luck would have it, Exidy 440 FPGA boards had been developed so I decided to take the plunge and get one so that this game is fixed once and for all (I cannot tolerate a non-working game in the collection). The cool thing about the Exidy 440 FPGA is it includes 12 different light-gun games that will all play perfectly on Cheyenne—my favorite being Crossbow. In fact, a few years back I already installed an Exidy 440 multi-game kit but one of the chips went south and it never really worked cleanly again. While a chip-based 440 multi-game solution cost less than a modern replacement board, I would argue the FPGA is a better bet given it helps you preserve a notoriously unreliable board system that will, sooner than later, give you headaches.

Exidy 440 FPGA Board

As illustrated above, the FPGA board is a fraction of the original board’s size, and it has various inputs for edge connectors for everything from the power source to the control panel to the coin door to the speakers to the video input for the monitor. There’s an easily accessible volume pot as well as a USB drive where you can load the ROMs for the various Exidy 440 games—you can see a full list of those games in the video below.

The FPGA board gives you a range of options for controlling settings for the cabinet as well as on a game-by-game basis.

In the Cabinet settings you can control things like global free play, determine if audio is  stereo or mono, decide what game you want to boot at startup, etc.

In the individual game settings you decide the number of lives (for Crossbow “friends”), difficulty, free play, coins, etc.

The FPGA pretty much solved all my board problems and gave me a dozen more games to boot, which is a definite win. I love it when a single board can play multiple games through upgrades like this.

With the board working the final piece was to swap out the speakers I’d blown with some relatively cheap ($26 on Amazon) 6″ car speakers that are 600W and 4 Ohm. With two of those installed with no shorting issues, I was able to enjoy the stereo effect for the first time with this game. Also, I have to assume the sound issues were board related, but that doesn’t make any sense given they checked out working  with Mike (and were working briefly for me)—that mystery is yet to be solved and may be a wiring issue, but wouldn’t that show up with the FPGA board? Nonetheless, I have a working Cheyenne and Crossbow with 11 additional games so the light gun situation at bavacade is on point!

Below are instructions I lifted from the KLOV forums and copied here for posterity.  Finally, big thanks to the wonderful community on KLOV, in particular BigDogs, for making things like the 440 FPGA a reality—it’s the stuff dreams are made of.

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INSTALLATION:

• Disconnect the original harness from the logic board OR EMI board. (some CABs have the EMI board and some don’t) All the connectors are different number of pins/pitch EXCEPT P4 (monitor) and P8 (speakers) . You may want to label these two before unplugging if you can’t easily determine which is which.
• Power up the game and verify the +5V. It’s common on these CABs for the 5V to be running significantly higher due to the large current draw and the loss in the wiring. If the 5V is higher than 5.2V you will want to adjust it down on the power supply. Instructions for this can be found in any of the Exidy 440 manuals. The board will run fine from 4.7V – 5.2V
• Power down the game and connect P3 (power), P8 (speakers), P4 (monitor), P16 (coin door), P12 (control panel) and P2 (gun). The “ramp” side of the harness connectors should face the “ramp” side of the connectors on the board. Note that the connectors on the FPGA board are orientated OPPOSITE of the original boards. You may have to remove (unscrew) one or more harness anchors to get enough slack to plug in all the connectors.
• Make sure no metal comes in contact with the edge connector or any of the component connections on the FPGA board.
• Power up the game and verify operation.

LOADING ROMS:

• Prepare a USB drive by copying the rom files to the root of the USB drive. Filenames are CASE sensitive so make sure the names EXACTLY match the names in the file list.
• Insert the drive into the USB connector on the FPGA board.
• Power up the game.
• While the files are copying the green active LED will flash/stay lit. When it goes out all the files are copied over.
• Power down the game and remove the drive.

SWITCHING GAMES:

There are two methods to switch games. The first method is hold the start button down and after 2 – 3 seconds start pulling the trigger. After 5 seconds each trigger pull will advance to the next game. You will see the selected game name show up at the bottom of the screen. When you get to the game you want to play just release the start and the game will run. The second method is to hold the start button down and DON’T pull the trigger for 5 seconds. This will bring up the title screen. Pulling the trigger will advance to the selection screen. You can then use the start button to highlight the game you want to play and then pull the trigger to load it.

SERVICE MENU:

The service menu can be entered any time there is a game running. (not from the selection screen or title screen) You enter the service menu by holding start AND trigger for 5 seconds. The service menu allows you to set the game options for each game and whether the game is “enabled” or not. (if it appears in the selection menu and game rotation) It also has the CABINET settings described below:

FREE PLAY- This is a “GLOBAL” setting that overrides all individual game settings. If it is enabled ALL games will be on free play.

FAST BOOT- When enabled the games will skip the power on tests and boot right into the game. If the EEPROM gets corrupted (high score table scrambled) OR on the very first time a game is run turn this off and the game will reset the EEPROM during the power on tests.

DIAGNOSTICS- When enabled causes all games to go into their diagnostics menus instead of running. This is where you will find the gun calibration and other tests specific to each game. Once enabled just switch games as you normally would but instead of running the game it will run the diagnostics.

AUDIO OUT- This allows you to select the type of audio to output, choices are:

• STEREO- This is the default setting and should be used for EXIDY cabs with TWO separate speakers, OR with Jamma alternate stereo speaker wiring. (+ = left, -=right, ground both speakers to a ground connection)
• MONO- This setting should be used for EXIDY cabinets with ONE speaker. (It will force ALL sounds in the stereo games to play out both channels)
• BRIDGED- This setting should be used with standard Jamma wiring where spk+ and spk- connect directly to the speaker and NO ground is used. It is mono but uses both amplifier channels in a bridged mode to increase the output power.

USE XBOW CAL- This setting causes all games to use the calibration data stored in the Crossbow EEPROM. I’ve found some games don’t seem to work well with this data so if you are having gun calibration issues I recommend calibrating each game using their respective diagnostic menus.

BOOT TO- This setting allows you to change the power up operation of the game. You can select a specific game to start up to OR the game selection or service menus. If the game you choose is not enabled, the next enabled game will run. If none are enabled the service menu will run.