Making Gauntlet Legends work with 8-way sticks (and NBA Jam)

demogo

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Making Gauntlet Legends work with 8-way sticks (and NBA Jam)

OK, I'm going to start a mini-blog of this sad saga here in the hopes that:

1) This will be useful to someone else some day
2) Someone here will look over my shoulder and suggest things
3) Someone here has already done this and can chime in

My goals are:

1) Swap the 49 way sticks out of my Gauntlet Legends game and swap 8 ways in.
2) Preserve the current Jamma harness at least up until where it mates with the control harness for P1 and P2.
3) Get NBA Jam to run in this same cab with the 8 ways and either use the same kick harness for p3/p4 for both games and swap them along with the Jamma harness *or*
4) Ideally wire up kick harnesses for both games and tie them together so I don't have to swap kick harnesses and can someday use a Jamma switcher for the main Jamma connections

OK, so here's my initial observations from pouring over the manuals and edge connector charts / wiring diagrams and asking questions here in other threads.

1) There is an 8-way joystick switch that can be thrown on the GL board
2) There is no edge connector chart for GL with the 8 way switch thrown; there is one for GL with the standard 49 way switch thrown
3) The 49 way edge connector chart uses some wildly non-standard things for the wires (player up/down bits, etc).
4) I have access to a Gauntlet Dark Legacy conversion kit guide that shows its edge connector chart for use with 8 way sticks and it appears standard
5) It is possible to convert GL to GDL by swapping out the hard drive and a couple of chips
6) There is a GDL conversion kit sold by Atari (I think) that would convert another game to GDL and it came with 8 way sticks.
7) There was also a dedicated GDL game sold that also used the 49 way sticks
8) The wiring harness coming up from the GL board ends in a .100 15 pin connector that plugs into a .100 15 pin connector control harness for each player. The P1 and P2 wires go the Jamma harness, the P3 and P4 wires plug into separate connectors on the GL board (not the Jamma harness).
9) The P3/P4 connectors that plug into the GL board are also .100 15 pin connectors
10) I've been told by others here that the kick harnesses are identical between GDL and NBA Jam. (Note that I said GDL, not GL)

OK, in the next message it begins to get interesting.
 
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I bought some NOS GDL kick harnesses for 8 way sticks and they just arrived today.

I wanted to see if they'd plug directly into the wiring harness coming up from the GL board to the control harness. (They are both .100 15 pin connectors).

They will plug in but there are problems. If you look at the edge connector chart for GDL conversion and look at the resulting wire color everything appears to line up nicely -- everything is in the right position with the kick harness.

So I went to the user input screen and began grounding the wires one at a time to ensure that everything was using the same wire color/position as described in the GDL conversion guide. The joystick directions and start button worked perfectly -- everything was on the right colored wire.

But then I discovered that the P1 fight/magic/turbo buttons were using some odd colors coming off the wiring harness that are not as described in the GDL conversion guide edge connector chart. (Remember, this is on a GL with the 8 way switch thrown). The wires that were supposed to carry the buttons (white yellow, white green, white blue) didn't do anything when I grounded them and when I grounded the odd color wires the game acted like the buttons had been pressed.

Well, okay. That sucks. I figured I was going to get off easy and not have to make up a proprietary connector and just use the kick harness but I guess not.

I had hoped that because you can easily convert a GL to a GDL with swapping a few chips that all I'd have to do is throw the 8 way switch on GL and I'd get the same behavior out of this board that the GDL conversion manual describes.

OK, onto the kick harnesses for what they were actually designed for.

I unplugged the existing kick harness for P3 that goes to the 49 way sticks and plugged in my shiny new GDL kick harness that runs directly to the P3 8 way joys and buttons. And when I grounded these one at a time I discovered something baffling -- again, all of the joystick directions worked perfectly and were on the correct wires as described in the GDL conversion manual and the P3 start button was too but again, the 3 buttons did not function for fight/magic/turbo.

What the HELL? It's the same board as GDL (I believe) with some different chips and I'd thrown the 8 way switch and plugged a genuine GDL NOS kick harness into the board and it doesn't work???

It's almost like the 8 way wire mappings are just broken. They're certainly undocumented. And they don't comply with the mappings documented in the GDL conversion kit.

What the hell? I can't believe that the behavior would be so different from a dedicated GL/GDL board with the 8 way switch flipped and a conversion kit GDL board.

Anyone got any ideas?
 
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I think some pictures may help illustrate the problems.

Are the player 1 & 2 buttons on the JAMMA Harness? If so, that may explain the wiring differences in the colors. While standardized some JAMMA harnesses don't always follow the color codes 100%, especially with the player buttons.

It is possible that the wiring was deliberately made to be incompatible between the games, just to stop people from doing what you are trying to do. Or GL could have beena first attempt and they had a better idea later that allows GDL & NBA Jam to swap in and out and just didn't retrofit GL.

If I follow your explaination correctly, I don't see any way short of having an adapter betwee the control panel and the game boards in order to facilitate swapping. You could just isolate the errant control lines and create a three headed adapter, one connector to the control panel and two connectors (one for each game) on the other. That would require you to switch the connectors when you switched the games, but it would put a logical order into the wiring.

ken
 
wow.. you had a lot of energy to type so much so early in the morning.. i wish this happened to you a year ago when i was in Houston for business..

post a pic of the GDL pinout and such.. basically, since there is a wire in the spot on the edge connector for the u,d,l,r button1,2,3, you should at least be able to bastardize an adaptor to play NBA jam.. what i dont think you will be able to do is have a 'switcher' to just swap to the other game.. you may have to connect/disconnect stuff to make it work.
 
Well, hopefully a picture will be worth 1000 words.

Here are 3 pics. 1st one is of the main P1 wiring harness to the controls harness. 2nd one is of the other side of the controls harness. 3rd is of the GDL kick harness.

The p1 and p2 controls hook up to the Jamma wiring harness. The p3 and p4 kick harnesses hook up to a special connector on the GL main board.

Note that the brown-white, orange-white, and yellow-white wires that are actually carrying the P1 buttons are not called out in the GDL conversion edge connector chart.

Next message will be of the relevant edge connector charts.
 

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And here are the relevant edge connector charts.

First the one for GL showing the standard 49 way joy mappings. This is also the mapping displayed in the GDL dedicated game (that also used 49 way joys).

The second one is what I've been working from and is from the GDL conversion kit sold by Atari that included and used 8 way joys. Everything seems to be on standard Jamma wires here.

I ASSUMED that when I threw the 8-way switch on the GL motherboard that the wire usage would be shifted to the same as displayed here but evidently not.
 

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wow.. you had a lot of energy to type so much so early in the morning.. i wish this happened to you a year ago when i was in Houston for business..

post a pic of the GDL pinout and such.. basically, since there is a wire in the spot on the edge connector for the u,d,l,r button1,2,3, you should at least be able to bastardize an adaptor to play NBA jam.. what i dont think you will be able to do is have a 'switcher' to just swap to the other game.. you may have to connect/disconnect stuff to make it work.

> wow.. you had a lot of energy to type so much so early in the morning..

It's funny you'd say that -- I was wiped out tired and if I had any sense I would have been in bed asleep. But I was surprised at first that it didn't work, then angry, then just deeply frustrated and it was the frustration that kept me going.

I've never worked in the video game business but do work for a company that produces electronic hardware and I'm really surprised that Atari didn't have just one common game board that they used for everything. It just doesn't make sense that they'd have different boards for GL, GDL, and GDL conversions when swapping a couple of chips will move you between the games.

I was bummed out but not shocked when I discovered that the kick harness wouldn't work correctly with the P1 wiring harness connector. It made a hell of a lot of sense that it WOULD because Atari could re-use parts that way and that would save them $$$.

I was deeply shocked when the GDL conversion kick harness wouldn't work on the GL with the 8 way switch thrown. What the hell? I can't figure out why they'd do this unless Ken's theory is correct and they were just taking action to keep people from converting their cabs to something else. But if someone really wanted to do that they'd just put a new Jamma harness in it anyway. (Something I'd like to avoid).

I do have the NBA Jam boards here now, btw, but I don't want to plug them in and test them until I can get this issue figured out.
 
OK, another very interesting fact.

These "special wires' that I noted that were carrying the button presses for the run, fight, turbo buttons do not actually hook into the Jamma harness at all. They appear to run to two special connectors on the far side of the sound I/O board labelled as p2 (gun 1 i/o connector) and p4 (gun 2 i/o connector). They are paired so that P2 handles the buttons for p1 and p2 and P4 handles the buttons for p3 and p4.

I have no idea of what the i/o connectors are really doing but the correct wires lead directly back to them. There are some jumpers that allow them to be configured for input or output mode. The GL manual defaults show them as being configured by default for input and so does the GDL manual.

HOWEVER, the wiring diagram for GL shows the jgun1 and jgun2 connectors as being used to control the buttons (which I've just confirmed via sight above) and the GDL conversion wiring diagram shows these as unused.

We need Jalpert or someone else that is successfully running GDL with 8 ways to check their P2 and P4 connectors and see if there's anything there.

It would also be fascinating to know the position of all of Jalperts U12 and U13 dip switch settings on the sound i/o board as well as the J1 through J8 jumpers. According to the GL guide and GDL conversion kit guide they should be the same except the GDL has the 8 ways switched on by default.
 
why dont you just start small.. V/18 through c/24 are the connections that are on your gauntlet 49 way and will map directly to the p1/p2 and 3 buttons for each - you just need to split the wires on the cp harness after connecting to the main harness.. this WILL work.. show us your control panel connector mated with the player 1 connector.

if it doesnt work for GDL 8/way, put the nba jam in there.. nothing will happen to the board, you just wont be able to control anything if it isnt connected.

i am not now/nor ever was an arcade tech, but hell, wiring a car stereo isnt much less complicated than this.
 
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