DEFENDER Green Label

[partschanger]

In another effort to get my REVERSE to work better I decided to try to play GREEN LABEL ROMS.

I burned my own and put them on a Later Series ROM Board. All ICs are 2716 except ROMS 2 and 3 which are 2532.

The game passes all power-up tests upon turn on and the attract mode comes up. I can cycle through all the Diagnostic Tests as well.

The Attract Mode wrongly lists the points scored for destroying a Lander as 100 instead of 150 so I know it is not RED LABEL.

The problem I am having is the game freezes immediately after hitting the START Button.

Also, the game no longer plays the second 'start-up' sound after the initial power-on tests like it does with the RED ROMS. I don't know if that is normal for GREEN ROMS or not.

Does anyone know why it doesn't play even though the self tests say it's good to go?

THANKS...

 

[partschanger]

Does this problem have something to do with the ROM Image being burned twice on each Chip?

 

[GA61XX]

What brand of 2716's have you used ??

 

[Jamesv833]

I'm not sure what issue you're having with reverse but I'm pretty sure there is a known issue where it won't work if you press another button right before(or something like that).
Here's a link to a product that's supposed to fix it, pretty sure it's the same dude who makes the zero play joystick kits.

Custom Arcade Machines | Swap Control Panels | Rotary Screen - ReverseFixer

New page

www.jbgaming.co.uk

 

[partschanger]

The 2716s are 'used' pulls with ST labels...

Even though they test good by the Burner and the Game they can still be bad?

And thanks for the REVERSE Fix link but I am already aware if it...

 

[mattosborn]

Let me guess.... You bought ST 2716's from eBay?

 

[GA61XX]

Ok.. ST brand EPROM's
i found they are voltage touchy
check you 5v line
i found one set i needed to run the EPROM's down at 4.8v to get them to work or would lock up & freeze

 

[partschanger]

Let me guess.... You bought ST 2716's from eBay?

You are correct... I do believe I did get these from EBAY a few years back when I first got the Burner. That alone could likely be the problem according to some of the old threads on here about it?

check you 5v line

Do you mean check the Game's 5V or the Burner's 5V?

Thank you Gentlemen for your replies on this I greatly appreciate your help.

 

[GA61XX]

The game's 5v..
try turn it down if using an after market switching type..
i have found these ST 2716 EPROM's run happy on their own .. but when in a set they lock up if voltage is over 4.9v

 

[GA61XX]

as for the "reverse" problem you first need to know the widget board is good
it could be a bad track, address line, header pins with dry joints , ribbon cable , or the 6821 chip has gone bad

 

[partschanger]

My DEFENDER still has the original power supply and I have 4.9 at the PIA on the ROM Board.

As for REVERSE, I have tried several Interface Boards as well as different CPU Boards and have gone over all the Control Panel wiring more than twice. I know there is a supposed Software Issue with REVERSE but it seems mine is failing more often than most other game's owners report. Since ALL of the Interface Boards are the same age it makes me wonder if they have the same problem.

This REVERSE Problem has been haunting me for quite some time now which is why I am trying to run GREEN LABEL because it only supports UPRIGHT cabinets and not COCKTAIL cabinets too.

I don't remember REVERSE being this problematic back in 1981....

 

[mattosborn]

I'm curious.... Is the reverse problem seen in Stargate as well, or is it just an issue on Defender?

 

[partschanger]

I have a STARGATE Boardset and Control Panel that I play on a ROBOTRON Cabinet and ......REVERSE...works....FLAWLESSLY.

When I hook up the DEFENDER Boardset that I have in it and use the STARGATE Control Panel REVERSE acts up. I chased this problem 20 years ago when I first got the beat up converted ROBOTRON Cabinet and I figured it to be a self made problem caused somehow by my creative wiring....

Fast Forward to May 2020 and I now have a dedicated upright all original Red Label Silverface DEFENDER that I got in hopes of having REVERSE be normal. But, unfortunately that is not the case so I am back to losing my mind over this problem....

 

[mattosborn]

I have a STARGATE Boardset and Control Panel that I play on a ROBOTRON Cabinet and ......REVERSE...works....FLAWLESSLY.

This is good news. We can infer that the input handling routines are different between the two. So it may be possible to modify the Defender code to behave more like Stargate.

 

[partschanger]

I want to know what the World Record Players have to say about this REVERSE issue... Does anyone know of someone they could ask about it? I know there is a Fakebook Group but it is private and I am not on the platform.

 

[mattosborn]

I want to know what the World Record Players have to say about this REVERSE issue... Does anyone know of someone they could ask about it? I know there is a Fakebook Group but it is private and I am not on the platform.

I bet it comes down to technique. They've just learned how to deal with it (avoiding the problem).

 

[GA61XX]

"reverse" This is sounding like we need 2 types of people to look into the problem
1) hardware side to look at the schematic
2) software , to look at both the Defender & Stargate to cross ref' each
as this "locking up" could be from either side
were if the PCB get's a double signal it freezes

Note:- when playing Frogger (original board) with a 8 way joystick & you clip the stick into one of the 4 corners (diagonal movement) the game will freeze... program can not handle both up/left (or any other combo)

But if this is a software "glitch" you must learn how to play with those rules ..

 

[mecha]

I don't even know what this is, or have ever heard of it.

 

[partschanger]

I guess it is time to get some 2716s from Arcade Parts and Repair so I can be sure the parts themselves are not the problem?

 

[mattosborn]

But if this is a software "glitch" you must learn how to play with those rules ..

Yeah, I kinda agree. If it is just a software issue, then it seems like a cheat to fix it. But if it's fairly easy to patch the problem, I suppose it doesn't hurt to make that available to people who are obsessively bothered by it....