Stargate/Defender II w/VTP: "Is it possible?"

[mikey.shake]

Hey Everyone --

 

So I've been playing a lot of Defender II (Stargate), and like some other people, I just can't get 100% comfy with the 2-joystick controls. I know I could buy a foot controller or something, but I really feel like it would be just about perfect if the 2nd controller utilized the Video Touch Pad or Keyboard/Kids Controller instead of the joystick.

 

I've looked and seen a number of other people asking something similar. But no definitive answers. I don't think a hack like this already exists or I would probably have found it around here somewhere. So I guess it's more of a matter of "Is it POSSIBLE, from a programming standpoint, to hack Stargate/Defender II to use the Video Touch Pad as the second controller?"

 

I suppose that a "yes" eventually would lead to "Has anyone worked on it?"/"Can someone do it?"/"What would it take?" questions in my mind. It's easier to hunt something if you know it exists. But if it's a moot point anyway...

 

I'm just wondering if I should bother holding out hope that one day I'll have my optimal version of one of my favorite 2600 games.

 

Anyone?

 

[+SpiceWare]

Haven't seen a hack for the keyboard controller. However, a number of games including it have been hacked to utilize a second button on a compatible gamepad. Amiga CD32 Joypad (primary: Red, secondary: Blue) as well as 3 and 6 button Genesis controllers (primary: B, secondary: C) are known to work.

 

http://atariage.com/forums/topic/158430-rom-hacks-to-support-2-buttons-with-genesis-controllers/

[mikey.shake]

Good to know, thanks!

[iesposta]

That equals this:

Use this as your second controller or get two for both controllers.

No hack required, and a lot nicer than using a touchpad.

[mikey.shake]

That is SEXY. eBay's giving me nothing, maybe I'm searching wrong. Where would someone acquire one of those, and what would it cost? That woodgrain is

 

Though... I'm still on the hunt for that magic hack. After all, my broke self already haS a Touch Pad...

Edited March 28, 2015 by mikey.shake

[accousticguitar]

Have you tried using the vtp on the game? Maybe one of the buttons already works by chance.

[+SpiceWare]

That equals this:

Use this as your second controller or get two for both controllers.

No hack required, and a lot nicer than using a touchpad.

 

Good suggestion!

 

That is SEXY. eBay's giving me nothing, maybe I'm searching wrong. Where would someone acquire one of those, and what would it cost? That woodgrain is

I dunno, I think mine's sexier by far

[Arenafoot]

I'd like to see some hacks using the Video Touch Pad and/or the CBS Omega Race Booster Grip too! (as I have both)

 

Is there any way to hack a VCS/2600 game to use the number pad from a Colecovision controller? or has it been done and I missed it?

[mikey.shake]

Have you tried using the vtp on the game? Maybe one of the buttons already works by chance.

Sadly, no luck. You'd think that at least ONE of them would work! But it was an idea definitely worth trying! And now it's on public record that it didn't work for me in case somebody else is searching for this.

 

... and good GOLLY does that Space Rocks design rule!

 

I don't usually use emoticons unless called for, but a "green with envy" one would be pretty good right now.

 

But still, I wonder... CAN it be done? I mean, I figure... but I don't know anything about programming!

[iesposta]

I would say probably cannot be done.

Reading the keypad takes a giant amount of processor time, and so much is happening in Stargate I would doubt any cycles amounting to 500+ (or whas that 500 milliseconds), either way I'd say it is too long to fit a keypad routing into (most) games.

 

Sadly, no luck. You'd think that at least ONE of them would work! But it was an idea definitely worth trying! And now it's on public record that it didn't work for me in case somebody else is searching for this.

 

... and good GOLLY does that Space Rocks design rule!

 

I don't usually use emoticons unless called for, but a "green with envy" one would be pretty good right now.

 

But still, I wonder... CAN it be done? I mean, I figure... but I don't know anything about programming!

[mikey.shake]

I would say probably cannot be done.

Reading the keypad takes a giant amount of processor time, and so much is happening in Stargate I would doubt any cycles amounting to 500+ (or whas that 500 milliseconds), either way I'd say it is too long to fit a keypad routing into (most) games.

 

It may not be the answer I was hoping for, but that's great info to know... thank you!

 

I guess it looks like one of those Starplex controllers just landed on my wishlist with a definitive "ka-blow"!

[+SpiceWare]

I would say probably cannot be done.

Reading the keypad takes a giant amount of processor time, and so much is happening in Stargate I would doubt any cycles amounting to 500+ (or whas that 500 milliseconds), either way I'd say it is too long to fit a keypad routing into (most) games.

 

 

I think it'd be possible. If I recall correctly from my experiments, the "giant amount of time" was basically waiting for the readings to stabilize after selecting a new row of the keypad to read. We only need to read 3 buttons (to select Smart Bombs, Inviso or Hyperspace) so just set the keypad to read the topmost (or bottommost) row during the console-init routine and leave it be.

 

If we needed to read multiple rows then just do something like this:

VerticalBlank:
  select keypad row
  run normal vertical blank logic
  read keypad row
 
Kernel:
  select keypad row
  run normal kernel
  read keypad row
 
Overscan:
  select keypad row
  run normal overscan
  read keypad row

[+SpiceWare]

I guess it looks like one of those Starplex controllers just landed on my wishlist with a definitive "ka-blow"!

 

0 bids, 37 hours left - http://www.ebay.com/itm/Atari-Lot-10-Games-And-1-Controller-/331515410878

[Nukey Shay]

Sadly, no luck. You'd think that at least ONE of them would work!

Think of the keyboard controller buttons as paddle controller positions instead of joystick on/off switches, and you can realize why it doesn't work. Not only is the means of reading the controller totally different, but the program would not be reading the correct register anyway.

[mikey.shake]

 

0 bids, 37 hours left - http://www.ebay.com/itm/Atari-Lot-10-Games-And-1-Controller-/331515410878

 

Of course... and me penniless until Thursday!! Thanks, though!

 

 

Think of the keyboard controller buttons as paddle controller positions instead of joystick on/off switches, and you can realize why it doesn't work. Not only is the means of reading the controller totally different, but the program would not be reading the correct register anyway.

 

 

Ahhh... that makes perfect sense. I know a little bit about electronics, but nothing about programming or this hardware. But now that you explain it I see why there's not much chance of one working by happenstance. I guess I sort of half-assumed (without having really considered it much) that the early VCS designers probably had to wring whatever they could to even get a keypad to work since they had so little to work with, like doubling down on functions and stuff. Thanks for explaining... this is how I learn!

[Nukey Shay]

Paddle triggers, however, are an example of reuse. The pair correspond to the left and right joystick movements...which can produce some odd effects if both happen to be held at the same time for joystick programs which do not invalidate such contradictory motion (Pac-Man, Combat, Wizard Of Wor, to name a few).

 

BTW replacing a Track And Field controller's cable with a standard joystick one would also work (merging the up and down wires with the left and right ones). Probably the cheapest alternative if you have that controller and an old joystick you no longer need.

 

Or, you could go the program hack route and use a Genesis controller...which is the cheapest alternative if you already own Harmony.

[CDS Games]

 

That equals this:

Use this as your second controller or get two for both controllers.

No hack required, and a lot nicer than using a touchpad.

 

This is sweet!

 

Ok let's say you start with a controller like this. Then add new buttons that switch on various combinations.

 

Button 6 = Left+ up

Button 7 = right + up

etc.

 

Assuming you have code that can finely parse out all the combinations of SWCHA, including the normally contradictory ones, could you in effect have a 31-button controller?

[CDS Games]

Though... I'm still on the hunt for that magic hack. After all, my broke self already haS a Touch Pad...

 

There's DIY as well. Can you scrape together enough money for these? https://www.sparkfun.com/products/9340

 

Set five onto a board, wire them into a broken joystick or temporarily disabled one, and you are in business.

[+SpiceWare]

This is sweet!

 

Ok let's say you start with a controller like this. Then add new buttons that switch on various combinations.

 

Button 6 = Left+ up

Button 7 = right + up

etc.

 

Assuming you have code that can finely parse out all the combinations of SWCHA, including the normally contradictory ones, could you in effect have a 31-button controller?

You could, but it wouldn't be very useful. When SWCHA came back as %10101111 the program would have no way to know if you pressed Left & Up at the same time, or button 6 by itself.

[CDS Games]

You could, but it wouldn't be very useful. When SWCHA came back as %10101111 the program would have no way to know if you pressed Left & Up at the same time, or button 6 by itself.

 

True enough. But let's suppose you rigged up a keyboard controller that has no practical use for combination functions. Like a QWERTY keyboard. Pressing T would be indistinguishable from (say) pressing ABD. But practically speaking, how often is ABD going to be pressed in combination when someone is typing?

 

Or say a fighting game where you have discrete buttons for each move, instead of joystick combinations (push fire & diagonal).

[+SpiceWare]

True enough. But let's suppose you rigged up a keyboard controller that has no practical use for combination functions. Like a QWERTY keyboard. Pressing T would be indistinguishable from (say) pressing ABD. But practically speaking, how often is ABD going to be pressed in combination when someone is typing?

 

Or say a fighting game where you have discrete buttons for each move, instead of joystick combinations (push fire & diagonal).

 

While anything could be done, the reality is it's highly unlikely it would be done.

 

As an example, we've known for over 4 years now how to do a simple modification to the Genesis controller which would allow all 4 buttons (A, B, C and START) to be read, but nothing's been done with that yet.

[CDS Games]

Probably not. Just thinking out loud.

 

Incidentally, I wonder how this one worked:

 

http://www.the-liberator.net/site-files/retro-games/hardware/Atari-2600/atari-2600-compumate-keyboard-by-specravideo-1983.htm

[+SpiceWare]

Probably not. Just thinking out loud.

 

Incidentally, I wonder how this one worked:

 

http://www.the-liberator.net/site-files/retro-games/hardware/Atari-2600/atari-2600-compumate-keyboard-by-specravideo-1983.htm

 

 

 

The keyboard is wired into the cartridge and the cartridge plugs into the joystick ports. If you download the source for Stella you'll find the details in CartCM.hxx.