Key features of this software update to Sterns 1977 Stingray are:

01. Freeplay support (optional).
02. Ability to disable Extra Balls or set Extra Ball to score Novelty points.
03. Option to advance Saucer potential on entry rather than from 10 point scores.
04. Reset Saucer potential value to 5,000 points at the start of a ball.
05. Option for Drop Target Special to score Novelty points.
06. Option for Outlane/Standup Target Special to award once per Drop Target bank reset.
07. Show *every* closed switch in switch test mode.
08. Include basic playfield attract mode lamp animation.

See the text file in the download for full listing of all the updates including DIP switch setting changes.

Interested parties will need to program replacement U2/U6 (E)EPROMs and jumper/modify their MPU board to support them.

[NEW enhanced version - work in progress. See post #46]
Update version: 31
Date:14-Apr-2022
Download from:
https://www.mediafire.com/file/em0es6fe4a0qpzp/Stingray_Update3_2022-04-14.zip/file

Update version: 14
Date: 24-Apr-2022
Download from:
https://www.mediafire.com/file/wp174k1zauwu9yr/Stingray_Update_2022-04-24.zip/file

Previous releases:

Update version: 13
Date: 17-Mar-2022
Download from:
https://www.mediafire.com/file/ve6j5w2cmcvm4yb/Stingray_Update_2022-03-17.zip/file

Update version: 12
Date: 25-Feb-2022
Download from:
https://www.mediafire.com/file/10nifx2qtglmfgd/Stingray_Update_2022-02-25.zip/file

[Reserved]

Details to come.

Actually there was a lot of "left over" code that I stripped out. I didn't look too deeply at it but seems like Stern might have rushed the release and removed features. More space could be freed up by optimising my changes better.

But I no longer see the point of keeping the original ROM footprint since modifying the MPU board to support two 2732 is the same work as modifying it to support two 2716. That's the reason for the reserved post above - but that's for another time

This game has too many switches and lamps connected together that really limits what can be done with a stock hardware build. If I owned a Stingray I'd rewire the replicated switches and lamps to give the rules more depth. Eg, the two standup targets, five right lane rollovers are all factory wired to the same switch as the spinner :-/

Yes, it was the same ROM.
The routine locations were re-organised compared to Bally so it wasn't a simple mod. I should document the left over code to see what game features were left out from production.

Presuming you have a Stingray, is rewiring switches and lamps something you could be tempted to do?

The first question is what rule changes to make if all five of the stingray lane rollover buttons, two standup targets near the pop bumpers and the special standup target were all wired as unique switches with their own feature lamps? Wires would have to be run from the lamp driver board to the playfield for controlling new feature lamps.

An idea I came up with was to make it so hitting both standups targets near the pop bumpers lights one of the stingray rollovers. Once you've done it five times to light all the stingray rollovers, it lights special at the standup target.

I'm not a fan of the advance bonus at the lower centre rollover button so I'd probably (option) disable it and make it so shooting all the way through the stingray lane over the five rollover buttons advances the bonus.

Maybe someone has some other ideas?

However my gut feeling is that uptake on these types of wiring mods might be done by one or two people and that's about it.

How about once you get it flipping, see what you think about the current ruleset and decide if you want it enhanced. You might even like the simplicity as is.

The short version of the rewiring mods is:
You run separate wires for each of the two standup target lamps, the five right stingray lane rollover button lamps, the 10X stingray lane lamp, the standup target special lamp and the drop target 10,000 lamp. That's ten wires from playfield lamps back to empty pins of J1 and J3 at the lamp driver board.
Rewiring these switches requires running new wires from existing playfield switches (mostly from the drop targets) to fill unused "intersections" in the switch matrix. Then once these items are unique there's scope to do things.

If/when I do any further work on this code, I'll likely be porting it over to my 7 digit scoring operating system.

I doubt I'd have it finished by TPF because of time constraints on my end but who knows.
What MPU board have you got and if it's stock can you modify it for EPROMs? BTW, I presume you have access to an EPROM programmer?

Yes, the factory MPU100 board had 9316 PROMs which are not fully pin compatible with EPROMs so the board will need to be modified. This future code update we're talking about here will require 2732 EPROM support. Three trace cuts and add three wires, see here:

https://pinside.com/pinball/forum/topic/converting-a-bally-17-to-35-mpu-with-fo597-service-bulletin#post-5270218

Correct, you can do it that way.

This is a preliminary playfield wiring change.

Green text indicates wires that need to be run back to the lamp driver board in the head with the connector location. Suggest you leave enough wire to be able to move the wires between J1 and J3 in case I need to move them around.
Note some of the lamps (five stingray lane rollover buttons and drop target 10,000 insert are factory wired as G.I). You'll need to disconnect the G.I from these and run the feature lamp 5.4V bus to them.

Yellow text is the playfield switch strobe wires that need to be run to the switches. Strobe #0 is at the outhole switch, Strobe #2 is at the 10 point and 50 point rebound switches. Strobe wires connect to the non-banded side of the diodes at the switches.

Pink text is the playfield switch return wires. These will all come from the drop target switches.

I hope it makes sense.

Stingray Playfield (Greyscale-Mods3b).jpg

Yes, I was thinking about adding some basic playfield attract mode lighting for the reason you mentioned, i.e. so the playfield doesn't look dead during game over.

Have you done any mods to your game yet regarding our discussion in this thread?

Cool! So you probably recognise where I got the playfield image above

The numbers in quotes are the VP lamp numbers you need:

LDB J1-28 "08" = #5 Upper rollover (Right Stingray lane)
LDB J3-04 "55" = #4 Upper middle rollover (Right Stingray lane)
LDB J3-27 "39" = #3 Middle rollover (Right Stingray lane)
LDB J1-07 "23" = #2 Lower middle rollover (Right Stingray lane)
LDB J1-16 "07" = #1 Lower rollover (Right Stingray lane)
LDB J1-13 "40" = Left Standup target
LDB J1-06 "24" = Right Standup target
LDB J3-02 "56" = Special Standup target
LDB J3-18 "58" = 10X Stingray lane
LDB J1-10 "22" = Drop Target 10,000

These quoted numbers are the new switch numbers:

"5" = #5 Upper rollover (Right Stingray lane)
"4" = #4 Upper middle rollover (Right Stingray lane)
"3" = #3 Middle rollover (Right Stingray lane)
"2" = #2 Lower middle rollover (Right Stingray lane)
"1" = #1 Lower rollover (Right Stingray lane)
"17" = Left Standup target
"18" = Right Standup target
"19" = Special Standup target

Note the new code is being built for two 2732 size EPROMs (Stringray is originally two 2716 size). It means you'll need to recompile PinMAME so it supports a new ROMset with Bally-35 addressing. I presume you know how to do this?? Anyway I'll need to talk to the PinMAME guys about it.

No problem, probably best that you wait for some code before doing the wire mods.
I've nearly finished porting the game code to my 7 digit operating system. My initial intention is to release something for "test" but with the newly wired lamps/switches configured to operate like they do now. Then work out how we make use of them.

Can you post your binary somewhere? (sendspace.com is anonymous and the link gets deleted after 30 days of no use).
I can check what's wrong with it.
If you concatenate the original factory Stingray code and program the exact same EPROM chip, does it work?

I know of a pinsider who has installed the update code and it is working.

I've included a basic playfield lamp attract mode in the enhanced code I'm working on. There is enough space to add it to the current release if you're ok to wait a a day or two for me to add it.

The file checksum looks good so it should work.
Which EPROM programmer are you using?
When you say the game doesn't boot, how many MPU board LED flicker/flashes are you getting?

Ok, it's coming

Ah I don't have experience with the Wellon programmers but I have the software loaded for demo.
Can you try this: in the Wellon software under "Setting" -> "Device Operation Options", set the "Verify Option" to "Twice VCC +/-10%" and then perform a verify operation on the EPROM you programmed against your concatenated file. Does it pass verification? If not, program (overwrite) the EPROM again (without erasing) so you basically double program it.

Wellon_Verify.png

Did you perform the verification at +/- 10% of VCC? This performs the verification at both 4.5V VCC and then 5.5V VCC.
I have seen a number of times personally and on Pinside where programmers successfully verify at 5.0 volts, but fail in the game because our games run the 5 volt supply rail around 5.3 volts which causes marginal programmed EPROM bits to error at higher supply voltage.

Added new update version 13 to the first thread post that includes a simple playfield lamp attract mode so the playfield now does something during game over.
Fixed a silly bug of mine from version 12 that activated the left slingshot instead of the saucers at power-up welcome.

Depending on your original ROM type they most likely won't boot. Right now if you double both the U2 and U6 2716 code and burn them to two 2732, it should work.

I've just about finished the code update, I should have something ready this weekend.

BTW I slightly changed the wiring for some lamps which programmatically made more sense. Will update the wire mod details above when I post the code.

Nice! thanks for the video.

Ok, I've uploaded the enhanced WIP code (based on the wiring changes to the lamps and switches mentioned) as it currently stands - I didn't get the time this week to finish it as I wanted, however it's pretty much all there and I wanted to get something out. See post #1 [version 31]

This enhanced code requires playfield lamps and switches to be rewired per post #22. The MPU board needs to be modified/already support two 2732 EPROMs in Ballys -35 MPU board fashion. ROM file for the Weebly MPU board also added.

The new rules revolve around the rewired two standup targets near the pop bumpers and the right side stingray lane rollover buttons:
- The two standup targets near the pop bumpers now individually light their corresponding lamp. Each time both lamps are lit/made, a stingray lane rollover button lamp is illuminated (in sequence).
- Making all five stingray lane rollover button lamps, lights the standup target lane for special.
- Lit stingray lane rollover buttons score 200 points each. 10X is still enabled via saucer entry when lit.
- Advance bonus can be enabled/disabled in new ways via software settings.

Other key features in the code are:
Millions scoring support
Enhanced navigation in diagnostic/audit mode plus new software settings mode.
Record highest credits to date when in freeplay reset mode.
Show highest scores/credits at start of the last ball.
Show previous scores before game was shut down.
Enable player scores only on players in game - flash their score at the start of a ball.
See full list of changes in the text file within the download.
The game updates in version 14 are all ported here.

@a_bord, I changed three VP lamp numbers regarding the two standup target lamps near the pop bumpers and the drop target 10,000 lamp. Post #29 has been updated accordingly.

The playfield wiring diagram in post #22 has also been updated for the adjusted connections of these lamps.

Yes!
Actually it came to mind to add it right before I posted the update but I was running late for something.
Post #1 download updated to include the Weebly ROM file.
Some 27256 might work as an alternative to a 27512. Just chop off the second half of the 27512 file and burn to a 27256 if that's what spare you've got handy

Updated the 2716 code to version 14. Fixed an error reported by ekthoren that the flippers were being enabled at the start of attract mode on power up.
Download link added to the first post.