- Thread starter Darksoft
- Start date
Monstermug
Professional
is that 158 a custom? if so that could be a project breaker. Be wise to start with that first?
ShootTheCore
Legendary
Oh I see now - the board that is used to add 3P and 4P to the Namco System 1 game Face Off is the same board used for Tank Force. I assumed before that FACE OFF was a brand name.
I checked the manual for Tank Force and an illustration shows the board.
That means 158 is certainly a Namco custom chip that would have to be reverse-engineered in order to make clones, or perhaps a logic analyzer could be attached to whichever JAMMA pins the daughterboard sends signals on to derive how the 3P & 4P controls are sent. Bravoman likely uses a different Namco custom chip on its daughterboard.
I checked the manual for Tank Force and an illustration shows the board.
That means 158 is certainly a Namco custom chip that would have to be reverse-engineered in order to make clones, or perhaps a logic analyzer could be attached to whichever JAMMA pins the daughterboard sends signals on to derive how the 3P & 4P controls are sent. Bravoman likely uses a different Namco custom chip on its daughterboard.
The first thing that comes to my mind is that it's simply muxing the inputs from 4 players down to 2. the only challenge there is that it relies on a trigger signal and JAMMA really doesn't have digital outputs.
Working on this assumption and looking at the schematic that @TMF68k put together it seems that trigger signal is would be the video sync. I'd be surprised if it's switching inputs on every pulse, so I'd suspect the chip has an internal divider for switching inputs. The crazy thing to me is that the sync signal passes through the chip as opposed to simply being sensed by the chip. Or maybe this was done to help ensure that the sync signal didn't degrade?
If this is the case I think this would be pretty straight forward to reverse engineer with a scope and a bit of time. If you did nothing else throwing a probe on the sync signal and then hold a button down and see what the pulse rate looks like on the output for that button the rest could be intuited. The resistor packs look like they're just there to act as pull ups and clean the input signals.
Does the game automatically detect when this PCB is attached or does it require a setting change? if it's auto detected then that might require some additional work to figure out.
EDIT: it looks like there's a separate ROM set for 4P tank-force. given that I see a 2P labeled romset for Faceoff but on 4P version I'm guessing that hasn't been dumped yet? Looking at MAME source it appears to confirm that these are multiplexed, but I haven't seen any indication as to what the switch frequency is.
Working on this assumption and looking at the schematic that @TMF68k put together it seems that trigger signal is would be the video sync. I'd be surprised if it's switching inputs on every pulse, so I'd suspect the chip has an internal divider for switching inputs. The crazy thing to me is that the sync signal passes through the chip as opposed to simply being sensed by the chip. Or maybe this was done to help ensure that the sync signal didn't degrade?
If this is the case I think this would be pretty straight forward to reverse engineer with a scope and a bit of time. If you did nothing else throwing a probe on the sync signal and then hold a button down and see what the pulse rate looks like on the output for that button the rest could be intuited. The resistor packs look like they're just there to act as pull ups and clean the input signals.
Does the game automatically detect when this PCB is attached or does it require a setting change? if it's auto detected then that might require some additional work to figure out.
EDIT: it looks like there's a separate ROM set for 4P tank-force. given that I see a 2P labeled romset for Faceoff but on 4P version I'm guessing that hasn't been dumped yet? Looking at MAME source it appears to confirm that these are multiplexed, but I haven't seen any indication as to what the switch frequency is.
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Rather than auto-recognizing the board, you can't operate it at all unless it's connected.
Faceoff is 2P. One team uses two levers and two buttons to control two people on one side. Naturally, you can't control them unless the boards are connected.
This is the same in multi-board.
The only difference from Tank Force is the coin and the start switch. This is not a part that is wired to this IO board, so it is not relevant.
Faceoff is 2P. One team uses two levers and two buttons to control two people on one side. Naturally, you can't control them unless the boards are connected.
This is the same in multi-board.
The only difference from Tank Force is the coin and the start switch. This is not a part that is wired to this IO board, so it is not relevant.
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do you have access to a oscilloscope or logic analyzer? I'd be really interested to see what the data on the buttons look like on the input and output compared to the sync line.
I have a suspicion that P2 buttons 2 and 3 are used to tell the mobo what bank is active.
I have a suspicion that P2 buttons 2 and 3 are used to tell the mobo what bank is active.
This time I just borrowed it for a short time to see how it worked.
I'll be able to check it out next time.
Some of the games seem to be behaving strangely.
I wonder if Merchen maze, splatter house, etc. are problems with getting random values. There may be others.
Is it doing something with keycus?
I can see that Splatterhouse has strange enemy movement in stage 6. Hell Chaos also seems to have strange attack patterns.
Pacmania does not show shadows when jumping.
I wonder if Merchen maze, splatter house, etc. are problems with getting random values. There may be others.
Is it doing something with keycus?
I can see that Splatterhouse has strange enemy movement in stage 6. Hell Chaos also seems to have strange attack patterns.
Pacmania does not show shadows when jumping.
I look forward to both of them and hope they are not too much for you.
Any information when there will be (or will there be?) another batch of these Namco System 1 multis? Saveyourgames has shown "Out of stock" for several months now.
Will still take time before I can buy more, but would be nice to know...
Will still take time before I can buy more, but would be nice to know...
skusuma
Professional
HighScoreSave.com still has the kits. You can check how much it'll cost to ship international.
Unfortunately there will be a lot of custom charges as well, not only costly shipping...
Coming from US... There is no way to avoid it stopping to customs office. +24% for the item and shipping costs. Yes, for both.
XtraSmiley
Legendary
Is there any benefit to have a US member mail it to you?
Benefits only with written "low value receipt".
XtraSmiley
Legendary
Let me know if I can help.
