Single Slot Coin Door dilemna

[codemonkey76]

I have a single slot coin door and I would like someone to be able to put coins in to load credits but have those credits shared between all players.

e.g. to play 4 player game, insert 4 coins. Or if playing a 4 player game and one player dies, they could just put a single coin in and join back in.

Is this possible with a single coin slot, or do i need separate coin slots for each player?

[Slippyblade]

Well, you could config MAME so that the same input counts for P1-P4 coin in.  But then a single coin would put a credit to each player.  And if, as in your example, P1 dies and drops a coin, EVERYBODY would suddenly have another credit.

With a few TTL chips it'd be easy enough to rig up a round robin type thing where first coin sends credit to P1, second to P2, third to P3, fourth to P4, fifith back to P1.  Kind of like a token ring type thing.  But then, back to your example, say the last credit went to P3 and P1 dies.  He'd have to put in a coin that would go to P4 then another coin that would go to P1 again.

Another option would be to wire 4 buttons AND gated to the coin slot.  So to load a credit for P1 you'd press and hold button 1 and drop a coin.  To load a credit to P3 you press button 3 and drop a coin.  Maybe wire it up so that if NO button is held it counts as P1.

To be absolutely honest though, it'd be WAY easier to just have 4 coin slots.

[codemonkey76]

hmm, I like your second option. how would I wire player 2's button 1 to both function as a normal button as well as have it being pressed and held in combination with a coin insert to trigger a player 2 coin?

[Slippyblade]

I'm a big fan of solid state circuits.  It'd use a single 7408 TTL chip. 

P1 Button-------
                       |----- P1 output signal
Coin Slot--------

P2 Button-------
                       |----- P2 output signal
Coin Slot--------

P3 Button-------
                       |----- P3 output signal
Coin Slot--------

P4 Button-------
                       |----- P4 output signal
Coin Slot--------

I can draw up an actual pinout/schematic later and show ya.  It'd literally be one chip since a 7408 has 4 gates on it.  It would take a little extra logic to get no button to default to P1 though.  Just so you know a 7408 chip is like 50 cents, maybe a $2 if you got it from Radio Shack.

[codemonkey76]

pinout/schematic would be much appreciated, you completely lost me with this, but I know someone who can help me and this may not be over their head.

[Slippyblade]

You would need to be using a 4 player encoder or have your keyboard/gamepad hack ready.  These diagrams assume a common ground.  With this setup if you dropped a coin without having a button down NOTHING will happen.

[PL1]

Not sure I get how things will work with your proposed setup, Slippy.

Seems like you'd need a boolean logic setup similar to this diagram with two AND gates, with one input inverted/negated.

(Yeah, I know the actual signal levels will need to be reversed for the typical active low encoder -- I'm just tracing the basic logic/timing here for a single player position.)

The problem that I see is that you will need to press and hold P1 Start before dropping in a token since the coin slot will only provide a momentary "1" on the blue line.

This will cause the encoder to output this sequence:

- P1 Start (Player 1 Start pressed and held, coin switch is open) - Red 1, Blue 0

- P1 Coin (Token momentarily closes coin switch) - Red 1, Blue 1

- P1 Start (Coin switch is open again, output continues until Player 1 Start button is released) - Red 1, Blue 0

Even if you dropped the top AND gate and took the red input straight to the encoder, you'd still always get a P1 Start while coining up.

Am I missing something here?


Scott

[Slippyblade]

The start switches aren't used, only the player COIN switches.  Think of the default MAME setup.  the '5' key is player 1 coin and the '1' key is the player 1 start.  so the button in this case would be wired to the player 1 coin input, NOT the player one start input.  You would still need to press the player 1 start after dealing with the coin slot and coin button.

Like I said, not my preferred method.  I'd either use 4 coin slots or just use coin buttons by themselves.  The OP is wanting some way to make a single slot coin mech work for 4 players.

[Zzap]

Having multiple credits from 1 coin doesn't have an effect on gameplay too much. In fact in quite a few games player 2 coin gives multiple credits to the single credit counter in the game anyway.

[PL1]

The way the original post was phrased, it didn't sound like he was planning on having four coin buttons on the CP.   

If there are buttons for Coin 1 thru Coin 4 on the CP why the    would someone bother with a circuit like this instead of just wiring Coin 1-4 to the associated encoder inputs and wire the coin slot in parallel with the (most often used) Coin 1 button?   

Another option that makes sense is to wire Coin 1 thru Coin 4 buttons to the encoder and wire the coin switch to all 4 encoder inputs using one diode per input (band toward the coin switch) so one coin drop gives you Coin 1 + Coin 2 + Coin 3 + Coin 4.  YMMV.


Scott

[codemonkey76]

You would need to be using a 4 player encoder or have your keyboard/gamepad hack ready.  These diagrams assume a common ground.  With this setup if you dropped a coin without having a button down NOTHING will happen.

I have an i-pac4

The way the original post was phrased, it didn't sound like he was planning on having four coin buttons on the CP.   

If there are buttons for Coin 1 thru Coin 4 on the CP why the    would someone bother with a circuit like this instead of just wiring Coin 1-4 to the associated encoder inputs and wire the coin slot in parallel with the (most often used) Coin 1 button?   

Another option that makes sense is to wire Coin 1 thru Coin 4 buttons to the encoder and wire the coin switch to all 4 encoder inputs using one diode per input (band toward the coin switch) so one coin drop gives you Coin 1 + Coin 2 + Coin 3 + Coin 4.  YMMV.


Scott

correct, i am not having any coin buttons on the CP, i was planning on just pressing (and holding) button 1 for each respective player when inserting a coin, not player x start button, can I do the proposed method using button 1, rather than player X start?

can I have it so that just inserting a coin without pressing a button would result in a credit for player 1?

[Binkles]

The way I would do it is buy one of those dial type switches, wire the wire that would normally go back to the 1 credit spot on the ipac to the middle pin of the dial, then wire the four positions on the dial to credits 1 to 4 on the ipac.

Leave the switch in position 1 for normal credit, twist the dial to positions 2 to 4 depending on which player enters the coin otherwise.

[PL1]

i am not having any coin buttons on the CP, i was planning on just pressing (and holding) button 1 for each respective player when inserting a coin, not player x start button, can I do the proposed method using button 1, rather than player X start?

can I have it so that just inserting a coin without pressing a button would result in a credit for player 1?

The one downside to the Button 1 approach is that some games use B1 as the start button.

Check the control panels for the games on your play list -- no dedicated start button usually means B1 doubles as Start.   

If you're going to the time, effort, and expense of making a 4-player panel and don't intend to include  coin buttons on the CP, I recommend getting a 4-slot coin door (Divemaster127 has them at arcadeemulator.net) or making the equivalent using CDRs from GGG or rectangular buttons from Divemaster with inserts that you print yourself.


Scott

[BadMouth]

Why not just map the controls in MAME to require one of the start buttons to be held down when a coin is inserted.
Map P1 coin to: P1 start button+coin switch
Map P2 coin to: P2 start button+coin switch
etc.

Only issue is that if they don't hold down a start button, then don't get a credit.
Not a big deal since this isn't for commercial use.

Personally I'd just have the coin door for looks and add a coin button next to the start button.

[JDFan]

OR just drill a hole in the door to mount a 4 way selector switch (like Pictured below) and wire it so that it credits the selected player number when a coin is inserted.

[codemonkey76]

Why not just map the controls in MAME to require one of the start buttons to be held down when a coin is inserted.
Map P1 coin to: P1 start button+coin switch
Map P2 coin to: P2 start button+coin switch
etc.

Only issue is that if they don't hold down a start button, then don't get a credit.
Not a big deal since this isn't for commercial use.

Personally I'd just have the coin door for looks and add a coin button next to the start button.

I would like the coin door to get some use and if i have coin buttons on the control panel, it will never get used, wheras, if i had a switch that could be toggled between coins and free play, it would see use. I am leaning towards just putting insert coin buttons on the control panel due to the dificulties. :-(

[lukensteinz]

Another option is using 4 small push buttons mounted on the coin door face plate.
I'd go with that instead of on the control panel.

Also if you have a coin mechanism which can lockout coins, then just wire it to reject coins unless selected player button is pressed.

Personally I'd go with my second option, be well worth the effort.
Even combine that with having player # buttons on the coin door ^_^

Sent from my Sony Xperia using Tapatalk.

[Slippyblade]

As cheap as coin doors are, I'd just have 4 coin slots.

[codemonkey76]

You would need to be using a 4 player encoder or have your keyboard/gamepad hack ready.  These diagrams assume a common ground.  With this setup if you dropped a coin without having a button down NOTHING will happen.

I think you are on the right track with this slippyblade, where does the VCC come from though, there is no "power pin" that I know of, on the keyboard encoder, to get a coin you just connect GND to coin1, or coin2, etc.

[yotsuya]

This was unintentionally the funniest thing I read today. 

[codemonkey76]

This was unintentionally the funniest thing I read today. 

How So?

[yotsuya]

As cheap as coin doors are, I'd just have 4 coin slots.

[othar]

i have the same problem... what i decided to to is to use one switch with the eject coin button and put another one on the path of the coin ... so it's like 2 switchs with only a single coin door.. perfect
it's up to you to choose the player for each switchs...