PROJECT: 1985 Gauntlet I made into a Dual Gauntlet (I & II) machine.

Teknotoyz

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PROJECT: 1985 Gauntlet I made into a Dual Gauntlet (I & II) machine.

I wanted to document my ongoing project of converting a dedicated Gauntlet I machine to a Dual boot Gauntlet I & II machine.
DISCLAIMER: There will be no harm done to the subject arcade machine!
PURPOSE: I have limited space, so 2 Gauntlet cabinets is out of the question. GII is supposed to be more fun, but GI is the classic (I want both!). :D

The original thread that caught my interest is here:
http://forums.arcade-museum.com/showthread.php?t=69472&highlight=gauntlet+rom+switch
I owe thanks to Steph for his help on this project.

SIMPLE THEORY:
Both Gauntlet I & II use the same hardware, conversion from GI to GII is simple, just replace/add 19 chips. To make a dual boot machine, there are 12 eproms that will need to be double sized to hold complete images for I AND II. When a switch is installed, the addressing changes from one to the other so the PCB only reads the desired game programming. While GII has more eproms, the GI program will ignore the extra ones when the switch is in GI mode.

As I have learned, this is cheaper to do when starting from a GII machine as you don't need the 6 dedicated GII eproms and single prom. Anyway, I placed the order, made the payment, and the GII and Dual chips arrived today. I will post pictures and updates as I get time to get everything installed. I will not be changing any cabinet artwork, it will remain Gauntlet I original.
 

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That's a pretty neat idea. I just got a Pleiades boardset to swap back and forth with my Phoenix. I wonder if those games are a rom difference only. I like the idea of just flipping a switch (I'm sure this would need to be done with the power off!) rather than having to disconnect one boardset and connect the other.

Let us know how this works out!
 
You do know that you can buy a working Gauntlet II board and plug it right in to your cab, right?

Yes, but why open your machine and handle old boards every time you want to play the other game. I'd rather just open the coin door, flip a switch and turn the game on to which ever one you choose. Very simple wiring and no board mods.
It was also cheaper to buy the chips (and will be more fun too!).
 
Yes, but why open your machine and handle old boards every time you want to play the other game. I'd rather just open the coin door, flip a switch and turn the game on to which ever one you choose. Very simple wiring and no board mods.
It was also cheaper to buy the chips (and will be more fun too!).
Good point. My expertise ends at installing a pre-fab multi kit like the Braze kits, that's why... :D Good luck with the project!
 
Good point. My expertise ends at installing a pre-fab multi kit like the Braze kits, that's why... :D Good luck with the project!

Yea, honestly, me too. This one should be pretty simple from what I have read. I decided to document it so others can get up the courage to try it if they want to.
 
I wanted to document my ongoing project of converting a dedicated Gauntlet I machine to a Dual boot Gauntlet I & II machine.
DISCLAIMER: There will be no harm done to the subject arcade machine!
PURPOSE: I have limited space, so 2 Gauntlet cabinets is out of the question. GII is supposed to be more fun, but GI is the classic (I want both!). :D

The original thread that caught my interest is here:
http://forums.arcade-museum.com/showthread.php?t=69472&highlight=gauntlet+rom+switch
I owe thanks to Steph for his help on this project.

SIMPLE THEORY:
Both Gauntlet I & II use the same hardware, conversion from GI to GII is simple, just replace/add 19 chips. To make a dual boot machine, there are 12 eproms that will need to be double sized to hold complete images for I AND II. When a switch is installed, the addressing changes from one to the other so the PCB only reads the desired game programming. While GII has more eproms, the GI program will ignore the extra ones when the switch is in GI mode.

As I have learned, this is cheaper to do when starting from a GII machine as you don't need the 6 dedicated GII eproms and single prom. Anyway, I placed the order, made the payment, and the GII and Dual chips arrived today. I will post pictures and updates as I get time to get everything installed. I will not be changing any cabinet artwork, it will remain Gauntlet I original.

You'll also need to double the EEPROM size and bank switch that too. Take a look at this site if you have not already:

http://www.ionpool.net/arcade/gauntlet/hacks/dual_boot_gauntlet_hack.html

EDIT: Looks like the same thing was linked in the other thread.
 
So I gave up, couldn't get the switcher to work!! grr...
G1 setup worked, and GII game worked, but G1 wouldn't play and GII setup failed...

My ROM source was just awesome, many recommendations to him, he helped me well above and beyond what he needed to!!

I do know that a ROM error upon startup is normal with this hack... just be forewarned if you go this route... I know a KLOV member here who was successful, but he now hates the process of doing this hack, very problematic...
 
Thats bad news! :(


I may want to look into this idea. Is there any documentation done on this kind of process?
 
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