HELP: SNES Tecmo Super Bowl/Franchise QB Hack

[QB8 0]

Hello-

Can anyone here point me in the right direction? I need some assistance with adding an additional layer to an already pre-existing hack for the SNES version of Tecmo Super Bowl.

Specifically, the franchise QB hack originally developed by Jstout & xplosv at Tecmo bowl.org. I just need help or some hacking ingenuity to maintain control of the QB after he throws the ball. Original hack: x19c41 = A9 F1 BF. Works great; however, the QB is motionless after throwing...would like to maintain control after throwing. Could anyone help out or point me in the right direction? As an incentive, I have a sealed copy of NES TSB up for grabs.

I can upload the ROM later or send privately.

Thanks in advance

[TylerBarnes 183]

More information would be needed for this sort of thing. To give people the best chance at helping, it is best to lay out the problem in a format that gives the other person everything they need to understand what the crux of the question is. Like what the hack is supposed to do, how the hack already works, what it doesn't do, and what you are trying to make it do, etc, etc. People are generally not going to be able to help if they need to further research independently just to understand what they are being asked. Modifying existing roms is complex, and modifying someone else's modifications can become even more complicated. 

Is the entire hack just replacing the A9 5F 9C  that normally exists at x19C41 and replacing it with A9 F1 BF? 

While I am not familiar with the ROM or what section of code it is, this could either be data or instruction code. The A9 at the beginning makes me believe it is code since A9 is the opcode for LDA immediate. If this is the case the only thing this hack has done is changed the value that gets loaded into the accumulator in that small section of code. 

So instead of LDA #$9C5F the instruction will execute LDA #$BFF1. Essentially just loading a different value to be used elsewhere.  However, without knowing the context, it is not really possible for me to tell you why this is relevant in the hack since I don't know where in memory it is getting stored, and for what purpose in the game's routines. 

The next part in the ROM of what I can assume is machine code (and not data), is 85 A5. Which is the instruction STA $A5. This instruction is storing the value loaded previously, but at a location on the Direct Page, since hex 85 is the opcode for STA in the direct page addressing mode. I can assume the Direct Page Register is set to $0000 since we find A9 00 00 5B in the initialization section of the ROM. 

This is could go on and on trying to turn hex numbers into opcodes, but I hope you see that this is not an easy ask. The original author of the hack might be best suited on questions regarding tweaks to their modification as they would have a deeper understanding of the section of code they are exploiting. 

Edited August 12, 2020 by TylerBarnes

[QB8 0]

Thanks for the response—I will try to clarify.

The hack was originally designed to mimic playing a single position in football or in this case, the quarterback. In Tecmo Super Bowl, offensive player control is determined by the player in possession of the football. In the ROM without the hack applied, control of the offensive player switches to the player in possession of the football.

As such, the existing hack mentioned above allows the player/quarterback to pass the ball to a receiver, running back, or tight end (RRBTE) and the cpu will then catch/run for you. However, this hack then renders the quarterback motionless unless he is hit by an opposing defensive player. 

The desired outcome would provide the player complete control of the quarterback as soon as he throws the ball to a RRBTE. Additionally, there is also a P1 icon that indicates who is in possession of the football. If a hack can be developed to allow “complete” control of the quarterback the P1 icon can still remain with the ball carrier without being modified  in any way.

Unfortunately, I lost contact with the original author of this hack—the site was abruptly shut down and I do not have access to the email interfaces.

If more clarification is needed, please let me know.

Thank you,

[QB8 0]

Good news! I tracked Xplozv down and he fixed that hack for me (X19C41 = A9F1BF & 19C4F = 4CC99B).  Stay healthy and be safe folks!