There is no way to disable Extra Ball as designed. It's going to require a ROM modification. You will need access to an EPROM programmer to go down this route.

Which means there's no way to disable it on Stern Pinball either, since it's the same rom. You want to tackle this one?

I guess no tournaments really use either title as this is the first time it's come up? Any other early mpu100 sterns that have this issue? (I already know about Dragonfist's)

Had a quick look, it's only Pinball / Stingray that doesn't have an Extra Ball disable dipswitch.

I presume your plate is full, but if you want this easy one go ahead otherwise I'll find time in a day or so and tie the option to one of the many unused dipswitches.

This game was at Pinburgh and I put up some good games and don't recall getting an extra ball, so I'd assume that they found a way to disable extra balls.

I never seem to collect the EB on mine. There might be a setting to have it change lanes or be on both lanes? I would have to check but that sounds familiar.
Mine switches lanes and it seems like the ball always goes in the opposite one.

Do the lanes do anything else useful? How crazy of an idea would it be to just disable the switches?

Either way...I'm super excited to see this one added to Titletown! Stingray was my first game...wish I would have kept it. Will be great to revisit it, and I'm sure yours will look and play way better than mine did!

I'm not sure if you'll like this approach but I wanted to keep it in the spirit of the other early Sterns. Let me know if you don't like it.

DIP switch 26 Off disables the Saucers extra ball feature.
DIP switch 26 On enables the Saucers extra ball feature.

When it's set to off, the Saucer now lights the "5,000" score instead of "Lites Extra Ball lane".
Other DIP switch game options of awarding extra balls instead of credits are unchanged. Same as other Sterns.

There is some unused code in this game that points to feature lamps which are not wired - I haven't investigated what they were meant to be.

Open the U2 ROM in a HEX editor and change the following:

Offset, original byte, new byte
$063: $E1 ---> $7F
$280: $11 ---> $1E
$281: $CB ---> $34

Open the U6 ROM in a HEX editor and change the following:
$4E4: $12 ---> $1B
$634: $00 ---> $D6
$635: $00 ---> $50
$636: $00 ---> $C5
$637: $00 ---> $02
$638: $00 ---> $26
$639: $00 ---> $09
$63A: $00 ---> $CE
$63B: $00 ---> $1E
$63C: $00 ---> $4A
$63D: $00 ---> $08
$63E: $00 ---> $4A
$63F: $00 ---> $26
$640: $00 ---> $FC
$641: $00 ---> $A6
$643: $00 ---> $97
$644: $00 ---> $1B
$645: $00 ---> $CE
$646: $00 ---> $85
$647: $00 ---> $08
$648: $00 ---> $7E
$649: $00 ---> $11
$64A: $00 ---> $CB
$64B: $00 ---> $01
$64C: $00 ---> $02
$64D: $00 ---> $05
$64E: $00 ---> $03
$64F: $00 ---> $05

Save and burn replacement 2716 EPROMs.

I've just tried this on my Stingray, works great! Thanks

Quench
Would it be possible to further develop this with minimizing the randomness of the saucer?
Something like it will only change the reward of the saucer when the saucer has been hit instead of some switch hits?

Yes, I can take a look.

So something like in this order?
(1) 5k
(2) Lite Spinner and Stingray Lane
(3) Double Bonus
(4) 55k
(5) Lite Extra Ball Lane (if enabled, or back up to 5k at (1) if disabled)

That would be really cool. Stingray is a fun game, but absolutely terrible for tournaments since the 55k is purely random and whoever gets it is practically assured the victory. You have to have a heck of a game to compete with someone who luckily fell in the 55k hole on the plunge. It should never be in a tournament as is in my opinion.

With a proper plunge you can move the pointer before the ball gets to the saucer.

Sort of. That's still a whole lot of luck from the rubber.

I'm looking at this now, it seems pointless to have the saucer relight potential for 2X, Spinner/Stingray lanes, and Extra Ball lane when the features are already lit.

Is it preferable to make the saucer alternate between 5k and 55k after the above mentioned are achieved? (seems too generous).
Or is it better to make 55k achievable only once per ball so the saucer lamp stops at 5k and no longer changes on the same ball?

i.e. Saucer lamp sequence:
(1) 5k
(2) "Lite the Spinner and Stingray Lanes"
(3) 5k
(4) "Lite Double Bonus"
(5) 5k
(6) 55k
(7) 5k
(8) "Lite Extra Ball Lane" (if enabled, otherwise just go back to (7) if disabled and stay there)

Sounds good to me

Done,
I've made other updates to the software and have created a separate topic for it.

Find details here:
https://pinside.com/pinball/forum/topic/stingray-stern-1977-software-update