Using Gameshark codes to add D-pad support to Nintendo 64 games

[triclon]

I have found a way to use the Gameshark to add D-pad support to Nintendo 64 games that previously lacked support.
The idea is to use the usual button activation codes to set the control stick activation code values.

Below is an example I have made for Mario Kart 64 (USA)

D0196504 0001
80196506 007F
D0196504 0002
80196506 0082
D0196504 0041
80196506 007F
D0196504 0042
80196506 0082
D1196504 8100
80196506 007F
D1196504 8200
80196506 0082
D1196504 8110
80196506 007F
D1196504 8210
80196506 0082
D1196504 A100
80196506 007F
D1196504 A200
80196506 0082
D1196504 A104
80196506 007F
D1196504 A204
80196506 0082

The above example is only for player 1.
196504 is the memory location for Player 1’s 16 bit button activator.
196506 is the memory location for y-axis Player 1’s control stick activator
These can be changed to the activators for players 2-4 if desired and multiple copies of this code can be made for each player so everyone can use the D-pad.
I have not yet added D-pad up and down support since this code is getting rather long, but it hardly affects the gameplay in Mario Kart 64.

I have tested this on real Gameshark + N64 hardware and it works quite well, at least for the example Mario Kart 64 code above. I don't know how many times the gameshark codes execute per second, but I haven't noticed any lag.

I think there is a lot of potential here. Now it is possible to create a code so Super Smash Bros. can be played with the D-pad. The c-buttons or any other buttons also could possibly be remapped allowing people to customize their own control scheme in games that lack such options.

[triclon]

One problem I have found is when trying to use 8 bit activators, the A button does not to work with any button combinations. For example, if set up an 8-bit activator for d-pad right + A button, I expect D0XXXXXX 0081 to work (80 for the A button + 01 for the d-pad right button) but it does not. The 16 bit version D1XXXXXX 8100 however does work. The problem with this is that all the buttons that are encoded in the 2nd byte (C buttons, R, and L) must now be accounted for so I then need to make copies of the activator for all possible button combinations with d-pad + A button + C,R, or L. This makes for very long gameshark code blocks, especially in games that make use liberal use of the c-buttons such as Super Smash Bros. If I could solve this problem, making gameshark codes to add D-pad support to games would become much easier. Anyone have any idea why the 8 bit button activators don't work for A + other buttons and if there is a way around this problem?