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Atari Vegas 3 Boards questions ?

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MonMotha:


--- Quote from: u_rebelscum on December 15, 2008, 03:17:34 pm ---
--- Quote ---If those can be used as GPIO, then that gives them all the inputs they need.  Blitz would likely only use an I-40 for backwards compatibility with Seattle, then.

--- End quote ---

Compatibility would make sense I guess.  But as I said, all the midway sports games need the I-40 regardless if vegas (NBA Showtime, Sportstation, Blitz 2000 Gold Edition) or seattle (Blitz, B99, B2000), while both the 3D gauntlet games don't, again regardless if vegas (dark legacy) or seattle (legends).  As you can see, Gauntlet Legends is seattle based, and didn't use I-40.

I think it's a Midway vs Atari thing.  NBA Showtime included two games, one being Blitz 2000.  So B2000 is on both seattle and vegas boards (I'm not sure on the amount of recoding done between the two, though).  And even though DL was released as a "Midway" game, it was written by the same studio as Legends (California based, "Atari Games" renamed to "Midway Games West"), while the sports games were written by the main Midway studio (Chicago based).  So IMO, DL is really an Atari game, running on "Atari Vegas" boards.

--- End quote ---

Seattle does not have those "GUN" inputs.  Seattle has JAMMA, P3/4 inputs, "Aux Latched Outputs" (which are used to control the I-40), Bill Input, and the Aux Inputs which are used for volume up/down like all other Midway games since the MK2 era.

I'm not sure I'd call it overengineered.  If somebody came to me with this problem (need more inputs), that's probably the exact solution I'd come up with, with perhaps some signalling differences.  Other popular option is to use a high speed serial bus, but Seattle again does not have a suitable interface (the serial port is only RS-232 at moderate bit rates).

u_rebelscum:


--- Quote from: MonMotha on December 15, 2008, 04:53:58 pm ---Seattle does not have those "GUN" inputs.  Seattle has JAMMA, P3/4 inputs, "Aux Latched Outputs" (which are used to control the I-40), Bill Input, and the Aux Inputs which are used for volume up/down like all other Midway games since the MK2 era.

--- End quote ---

Ah,  gotcha.  (My bad, Legends is Atari Vegas, not seattle. d'oh)  Backward compatable makes way more sense.

You don't happen to know where I can get a copy of a seattle game operator manual?  I have a bunch of vegas game manuals, but nothing on seattle games.


--- Quote from: MonMotha on December 15, 2008, 04:53:58 pm ---I'm not sure I'd call it overengineered.  If somebody came to me with this problem (need more inputs), that's probably the exact solution I'd come up with, with perhaps some signalling differences.  Other popular option is to use a high speed serial bus, but Seattle again does not have a suitable interface (the serial port is only RS-232 at moderate bit rates).

--- End quote ---

You seem to know a lot more about this multiplexer thing method of input than I do.  Do you mind if I go OT and ask theory and practice of it?

Is it easier to multiplex to one set of pins of both X and Y axes and all four players, or say, two sets, one for X one for Y, multiplexed for the players, or maybe the other way, each player has its four pins multiplexed for X and Y?  (I guess IOW, why choose this way?)  Is it really an 8x multiplex like I've said, or is it more?  (Reason I ask is there is plugs for five players on the I-40, plus the output and the timing/power.)  How is the info demultiplexed? 

The reason I'm asking is I want the 49-way inputs emulated in mame for these games, but need to know more if I'm going to try to code it myself.  (How should multiplexing be emulated?  Can I just skip the mux/demux steps?)

MonMotha:


--- Quote from: u_rebelscum on December 15, 2008, 06:52:06 pm ---
--- Quote from: MonMotha on December 15, 2008, 04:53:58 pm ---Seattle does not have those "GUN" inputs.  Seattle has JAMMA, P3/4 inputs, "Aux Latched Outputs" (which are used to control the I-40), Bill Input, and the Aux Inputs which are used for volume up/down like all other Midway games since the MK2 era.

--- End quote ---

Ah,  gotcha.  (My bad, Legends is Atari Vegas, not seattle. d'oh)  Backward compatable makes way more sense.

You don't happen to know where I can get a copy of a seattle game operator manual?  I have a bunch of vegas game manuals, but nothing on seattle games.

--- End quote ---
I have a scanned copy of 2 player Blitz, but that doesn't detail the 49-way wiring.  I had to infer all of that from a wiring harness I got in order to make it work.


--- Quote from: u_rebelscum on December 15, 2008, 06:52:06 pm ---
--- Quote from: MonMotha on December 15, 2008, 04:53:58 pm ---I'm not sure I'd call it overengineered.  If somebody came to me with this problem (need more inputs), that's probably the exact solution I'd come up with, with perhaps some signalling differences.  Other popular option is to use a high speed serial bus, but Seattle again does not have a suitable interface (the serial port is only RS-232 at moderate bit rates).

--- End quote ---

You seem to know a lot more about this multiplexer thing method of input than I do.  Do you mind if I go OT and ask theory and practice of it?

Is it easier to multiplex to one set of pins of both X and Y axes and all four players, or say, two sets, one for X one for Y, multiplexed for the players, or maybe the other way, each player has its four pins multiplexed for X and Y?  (I guess IOW, why choose this way?)  Is it really an 8x multiplex like I've said, or is it more?  (Reason I ask is there is plugs for five players on the I-40, plus the output and the timing/power.)  How is the info demultiplexed? 

The reason I'm asking is I want the 49-way inputs emulated in mame for these games, but need to know more if I'm going to try to code it myself.  (How should multiplexing be emulated?  Can I just skip the mux/demux steps?)

--- End quote ---
I haven't looked into exactly how the I-40 board works, but most of these (there's also one in DDR and PIU, for example) work by having a reset line which puts the CPLD on it into a known state and then having the game board clock its way through various muxing options.  On DDR, there is a fixed bit pattern that shows up as you work your way through the states which allows detection.  The I-40 is probably similar.

As far as "ease" of how to arrange things, as far as hardware is concerned, it's just bits.  The software then takes those bits back apart and handles them as it pleases.  For 49-way sticks, that's likely a small lookup table since the bit patterns don't have a lot of meaning without any massaging, so if you want to change the order of things around, it's just a matter of modifying your lookup table.  IIRC, there are 4 input bits from the I-40 (shows up on P3's 8-way joystick input), so I suspect it just does a "left-shift 4 and OR" thing to get the original 8-bit 49-way "code" recovered.  That would mean a 8:1 mux if that's what you're referring to since the number of output lines is 1/8th the number of input ones (2:1 for each player and 4 players).  If there are other states to allow detection of the I-40 (likely, since it can detect it), there may be additional states.  The PLD on the I-40 isn't too complicated, so it is likely a simple state machine like DDR.

As far as emulation, it would probably be best to emulate the I-40.  The de-muxing looks to be handled entirely in software, so if you don't emulate the hardware, you'd have to patch the game software, which kinda goes against the idea of "full emulation".  MAME emulates the IO board for DDR, if you want a reference point.

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