Adding second fire support to some C64 games

[crystalct]

MONTEZUMA'S REVENGE

Games System compatible (keyboard is optional).

Optional commands:
FIRE or UP + FIRE to start level 1
DOWN + FIRE to start level 2
LEFT + FIRE to start level 3

No 2nd fire, just playable on C64 GS

Download CRT or PRG

[Snarko]

MONTEZUMA'S REVENGE

Optional commands:
FIRE or UP + FIRE to start level 1
DOWN + FIRE to start level 2
LEFT + FIRE to start level 3

No 2nd fire, just playable on C64 GS

Greatly appriciated!
Hmm, I wonder if Jumpman JR would be possible to make C64 GS compatible? I always play that game with 1 player and speed=4 (I think 4 was meant to be normal/default?) so perhaps if those values could be defaulted if pressing the fire button?

Another suggestion, Hover Bovver to be C64 GS:ed. For me it'd enough to just be able to start the game with FIRE (F7 is used in original game)! Maybe also selecting "Entry Lawn" with 2nd fire?

Not ideal solutions I know, just my humble suggestions!

[crystalct]

JUMPMAN JUNIOR

Games System compatible (keyboard is optional).

Menu optional commands:
FIRE to select values
UP and DOWN to change values

No 2nd fire, just playable on C64 GS

Download CRT or PRG

[Snarko]

JUMPMAN JUNIOR
FIRE to select values
UP and DOWN to change values

Works superb and a much better implementation than my previous somewhat naive suggestion, thank you!

[crystalct]

HOVER BOVVER

Games System compatible (keyboard isn't required).

Menu commands:
Joystick to set values
FIRE to start

No 2nd fire, just playable on C64 GS

Download CRT or PRG

[Snarko]

HOVER BOVVER

One of Minters finest and most unique for sure, the music get stuck in your brain "Bubble bobble"-style, thank you crystalct!

[crystalct]

ENTOMBED

Games System compatible (keyboard is optional).

Optional commands:
2nd FIRE to change action
3rd FIRE + DOWN to pause
3rd FIRE + UP to restart

Download CRT or PRG

[mrr19121970]

I think I've found the cause of the problem.
Mouster interface for connecting modern mice/gamepads <---
And probably other electronic devices that are used for these purposes.

It seems to me that the voltage stabilizers that these devices have cause the voltage supplied to potX and potY to be slightly lower than the voltage they receive from the C64 side (+5V line)
This difference means that we will never get a reading of the full $00 from $dc00.
$ff (for open, button 2 or 3 released) will always be ok.
But pressing the button (short to the 5V line) will never perfectly give $00
The higher the voltage (or too low for stabilizer) of the PSU power supply, the greater the difference on the potX and potY lines of these electronic devices.

I just checked it on two C64 PSUs.
The first PSU supplies +4.8V to the Joy port
The second PSU supplies +5.1V to the Joy port

On the first PSU, reading $d419gave $0f.
On the second one he gave $07
And connected Paddle gives $00 when you turn the knob all the way.

Its seems that MouSTer is not providing perfect 2 button results. https://retrohax.net/shop/modulesandparts/mouster/

this means that the GITHUB code snippet should be adjusted to allow BPL (ie $00-$7f) to be considered as a button-2 press and BMI (ie $80-$ff) to be no button-2 pressed.

[Tobias]

I don't see why it couldn't be 0 and $ff ... unless the device does something really strange and broken

[crystalct]

In my mods the second (and third) fire are considered "pressed" if the value read by the potx (or poty) is less than or equal to $0F

[minotaurus]

Hi CrystalCT, thanks for your work, really appreciated
Any chance to see a 2-3 button version of "Mask 3 - Venom Strikes Back"?
I think would be nice to have a button for select the four slot instead of keyboard (maybe like potx+up for 1, potx+down for 2 and so on).
Thanks again!

[crystalct]

Hi CrystalCT, thanks for your work, really appreciated
Any chance to see a 2-3 button version of "Mask 3 - Venom Strikes Back"?
I think would be nice to have a button for select the four slot instead of keyboard (maybe like potx+up for 1, potx+down for 2 and so on).
Thanks again!

I will Try.

[crystalct]

HE-MAN AND THE MASTERS OF THE UNIVERSE: THE ILEARTH STONE

Games System compatible (keyboard is optional).

Commands added:
2nd FIRE to jump
FIRE to start and to restart after game over
Note: UP is no longer available for JUMP, to avoid unwanted jumps

Download CRT or PRG

[Sparky-D]

That's an interesting thread, definitely. Because a second button, really does improve playability, in some games.

It would be really great, if a second firebutton could be used in the game "Oy Up" (a good "Puyo Puyo" clone) to turn the falling pieces in the other direction than firebutton-1. In all console versions of "Puyo Puyo" you can turn the pieces in both directions, in "Oy Up" unfortunately only in one and that's not ideal in the higher levels of the game, where the pieces fall down quite fast, because turning a piece to the right three times, simply takes more time, than turning it one time to the left.

But i guess, such a change, will probably be a complex thing, because turning pieces in the other direction too, is not possible in the current version of the game. But it would be great in any case and improve the playability greatly. What do the 2-button-hack specialists here think, technically feasible, or rather not?

[crystalct]

That's an interesting thread, definitely. Because a second button, really does improve playability, in some games.

It would be really great, if a second firebutton could be used in the game "Oy Up" (a good "Puyo Puyo" clone) to turn the falling pieces in the other direction than firebutton-1. In all console versions of "Puyo Puyo" you can turn the pieces in both directions, in "Oy Up" unfortunately only in one and that's not ideal in the higher levels of the game, where the pieces fall down quite fast, because turning a piece to the right three times, simply takes more time, than turning it one time to the left.

But i guess, such a change, will probably be a complex thing, because turning pieces in the other direction too, is not possible in the current version of the game. But it would be great in any case and improve the playability greatly. What do the 2-button-hack specialists here think, technically feasible, or rather not?

In the case of OyUp, which is a game developed recently, you should ask to developer directly, especially when it is not a simple "hack", but a non-trivial addition of code. The action you mention wasn't exactly foreseen.