The Two Tigers boardset that I used to make the mcr mulitigame was identical to
a tron boardset with the following changes made by cutting traces and 
resoldering jumper wires.  I believe this was done to ensure that a romswap of
copied two tigers roms could not convert a standard tron boardset to a two 
tigers.  This was done because bally/midway wanted to sell the tron to two 
tigers conversion upgrade kit. 

(XN:M means device at location X,N on the CPU board, on pin M)

Traces cut:

Orignial Source			Opened Destination (cut nearest here)
J6:21				D10:2
B6:5				D10:5
B6:3				D10:11
J6:17				D11:2
J6:18				D11:5
J6:19				D11:11
J6:20				D11:14
J6:13				D12:2
F10:12				D12:2
J6:14				D12:5
J6:15				D12:11
J6:16				D12:14

B6:3				B7:14
J6:19				G10:5


Jumpers Added:

New Source			Modified Destination
J6:20				D10:2
J6:21				D10:5
B7:5				D10:11
J6:16				D11:2
J6:17				D11:5
J6:18				D11:11
J6:19				D11:14
B6:3				D12:2
F10:12				D12:5
J6:14				D12:11
J6:15				D12:14

B6:3				G10:5
J6:19				B7:14

F10:12		(MOD Fix)	J6:13


This has the effect of doing the following to the background ram:

New Signal	Original Signal Replaced	On Device
BuA10		BuA0				D12:2
BuA0		BuA1				D12:5
BuA1		BuA2				D12:11
BuA2		BuA3				D12:14
BuA3		BuA4				D11:2
BuA4		BuA5				D11:5
BuA5		BuA6				D11:11
BuA6		BuA7				D11:14
BuA7		BuA8				D10:2
BuA8		BuA9				D10:5
BuA9		BuA10				D10:11

These first mod effectively rotate the background video ram address bits A0-A10
left one bit.  The other mod affects the pallette ram:

New Signal		Original Signal Replaced	Device : Pin Number
BuA6			BuA10				B7:14
BuA10			BuA6				G10:5

This causes most of the palette to be incorrect and the majority of the screen 
elements come out red.  If you would like to convert your standard Tron 
(or mcr2 equivalent) boardset to a dedicated Two Tigers you need to make the 
trace changes mentioned above.  The dedicated version of Two Tigers is 
slightly different to the upgrade version in many electrical and gameplay 
ways:

Two Tigers Dedicated (Yoke Version)	Two Tigers Upgrade (Spinner Version)
- Additional control "speed"		- No speed function, speed is constant
- Steering controlled by a pot		- Steering controlled by an optical 
  with an A/D converter	 		  encoder on a spinner
- Different interface locations		- Different interface locations
- Ship graphics vary			- Ship graphics vary
- Some stages occur at dusk,		- All Stages occur during the day
  night, dawn and day.
- No crashes involve parachuting	- All crashes include pilot escape with
  escapes except in between stages	  parachute
- Ships shoot from cannons 		- Ships shoot to crosshairs
- No plane engine noise 		- Player planes have background engine sound
- Background music was provided		- There was no background music
  by a tape
- Different high score music		- Different high score music
- Dogfight invoves protecting your	- Dogfight involves shooting down the
  aircraft carrier from sinking by	  opponent's aircraft and avoiding the
  the opponent				  crosshairs.
- Sea Level is close to ship		- Sea level is halfway up the screen
- Game Designers Names apear		- Only Bally / Midway appears in 
  in attract mode			  attract mode
- Hero Table for Dogfight mode		- There is no Hero table for Dogfight mode
  is shown in attract mode
- Cloud graphics are repetitive		- Cloud graphics have middle line mirrored
					  horizontally for better appearance
- Ship has no wake			- Ships have a wake