Centipede: Player input circ. vs. joystick circ.

texasmame

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Trying to get my Centipede board back to recognizing the tracball.

D9 says it is tied to TRB0 thru TRB4 (presuming these are the four tracball directions) but it also is under the heading "joystick input circuit."

L9 says it is also tied to TRA0 thru TRA4 but it is under the heading "player input circuit."

Of course, below all that is "mini-trac ball circuit" but since this is an upright, that ain't it - er. . . is it?

So, on an upright with an original, unhacked harness, which reads the tracball - D9 or L9?
 
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Trying to get my Centipede board back to recognizing the tracball.

D9 says it is tied to TRB0 thru TRB4 (presuming these are the four tracball directions) but it also is under the heading "joystick input circuit."

L9 says it is also tied to TRA0 thru TRA4 but it is under the heading "player input circuit."

Of course, below all that is "mini-trac ball circuit" but since this is an upright, that ain't it - er. . . is it?

So, on an upright with an original, unhacked harness, which reads the tracball - D9 or L9?

Hey. Good to see someone making the effort to make sense of schematics.

Regarding "mini-trac ball", that doesn't refer to a mini cabinet (Atari called them "Cabaret" cabinets). "Mini-trac ball" was just the trademark name Atari used for the track ball unit back then; look thru the manual (TM-182) to see that.

The schematic shows inputs for 2 trackballs. This is because the same PCB is used for both upright and cocktail games. The 2nd player trackball inputs aren't used in your upright game. Notice how all of the player 1 trackball inputs (1 horiz dir, 1 horiz clock, 1 vert dir, 1 vert clock) go to the "A" inputs of the selector @ D/E11 (LS157). The "FLIP" line is used to select which inputs go thru to the outputs; this allows the game to read the player 2 trackball when it flips the screen for PL2. It should always pass the pl1 inputs for an upright, as the FLIP line should never change state. Thus, everything downstream of here is used for both PL1 and PL2. Also note that trackball inputs are not directions; they are "clocks" (pulses) and a direction signal (high for one rotatal direction low for the other) for each axis (horizontal and vertical). The horizontal clocks and direction signals then go to a flip-flop and counter (D11 & C11). The vertical signals go to another flipflop and counter (the other half of D11 & B11). The outputs of these counters are TRA0-3 (which are horizontal data), and TRB0-3 (which are vertical data). TRA0-3 next go thru the LS257 @ L9 ; that IC lets the game choose between reading the horiz trackball data, or the fire buttons and start buttons. The TFB0-3 data goes thru the LS257 @ D9 ; that IC lets te game choose between reading the vert trackball data, or the (optional) joystick 2 inputs.

At that point, we're to the data bus, address bus, and select circuity. If you're having an issue with horiz or vert, look at the appropriate areas. If neither horiz or vert work, maybe look upstream, at the E/F11 inverters, or the D/E11 selector... or the trackball itself.
 
Hey. Good to see someone making the effort to make sense of schematics.

Regarding "mini-trac ball", that doesn't refer to a mini cabinet (Atari called them "Cabaret" cabinets). "Mini-trac ball" was just the trademark name Atari used for the track ball unit back then; look thru the manual (TM-182) to see that.

The schematic shows inputs for 2 trackballs. This is because the same PCB is used for both upright and cocktail games. The 2nd player trackball inputs aren't used in your upright game. Notice how all of the player 1 trackball inputs (1 horiz dir, 1 horiz clock, 1 vert dir, 1 vert clock) go to the "A" inputs of the selector @ D/E11 (LS157). The "FLIP" line is used to select which inputs go thru to the outputs; this allows the game to read the player 2 trackball when it flips the screen for PL2. It should always pass the pl1 inputs for an upright, as the FLIP line should never change state. Thus, everything downstream of here is used for both PL1 and PL2. Also note that trackball inputs are not directions; they are "clocks" (pulses) and a direction signal (high for one rotatal direction low for the other) for each axis (horizontal and vertical). The horizontal clocks and direction signals then go to a flip-flop and counter (D11 & C11). The vertical signals go to another flipflop and counter (the other half of D11 & B11). The outputs of these counters are TRA0-3 (which are horizontal data), and TRB0-3 (which are vertical data). TRA0-3 next go thru the LS257 @ L9 ; that IC lets the game choose between reading the horiz trackball data, or the fire buttons and start buttons. The TFB0-3 data goes thru the LS257 @ D9 ; that IC lets te game choose between reading the vert trackball data, or the (optional) joystick 2 inputs.

At that point, we're to the data bus, address bus, and select circuity. If you're having an issue with horiz or vert, look at the appropriate areas. If neither horiz or vert work, maybe look upstream, at the E/F11 inverters, or the D/E11 selector... or the trackball itself.

Tested the board with a known good tracball - was getting direction only one way; kinda down and to the left.

My tracball inputs were both hosed - no movement on a known good boardset.

This is also the game I was having the G07 red issues with.

Think it's haunted. :(

Have a known-good boardset on the way so having that on hand should go a long way to troubleshooting.

I went ahead and replaced D9 and L9 with new chips and socketed them. Now, just gotta work on the opto boards to see if there are any changes in the board's status.
 
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I have 2 tubs of trackballs that I picked up at the last auction... LOTS of trackball parts. :/
 
Well, I picked up those 3 types of chips and piggybacked them on there to no change.

Hey. Good to see someone making the effort to make sense of schematics.

Regarding "mini-trac ball", that doesn't refer to a mini cabinet (Atari called them "Cabaret" cabinets). "Mini-trac ball" was just the trademark name Atari used for the track ball unit back then; look thru the manual (TM-182) to see that.

The schematic shows inputs for 2 trackballs. This is because the same PCB is used for both upright and cocktail games. The 2nd player trackball inputs aren't used in your upright game. Notice how all of the player 1 trackball inputs (1 horiz dir, 1 horiz clock, 1 vert dir, 1 vert clock) go to the "A" inputs of the selector @ D/E11 (LS157). The "FLIP" line is used to select which inputs go thru to the outputs; this allows the game to read the player 2 trackball when it flips the screen for PL2. It should always pass the pl1 inputs for an upright, as the FLIP line should never change state. Thus, everything downstream of here is used for both PL1 and PL2. Also note that trackball inputs are not directions; they are "clocks" (pulses) and a direction signal (high for one rotatal direction low for the other) for each axis (horizontal and vertical). The horizontal clocks and direction signals then go to a flip-flop and counter (D11 & C11). The vertical signals go to another flipflop and counter (the other half of D11 & B11). The outputs of these counters are TRA0-3 (which are horizontal data), and TRB0-3 (which are vertical data). TRA0-3 next go thru the LS257 @ L9 ; that IC lets the game choose between reading the horiz trackball data, or the fire buttons and start buttons. The TFB0-3 data goes thru the LS257 @ D9 ; that IC lets te game choose between reading the vert trackball data, or the (optional) joystick 2 inputs.

At that point, we're to the data bus, address bus, and select circuity. If you're having an issue with horiz or vert, look at the appropriate areas. If neither horiz or vert work, maybe look upstream, at the E/F11 inverters, or the D/E11 selector... or the trackball itself.
 
Not too long ago I fixed a friends centipede game. it didn't seems to track very well. The problem was the connectors to the track ball wasn't very tight. I replace the connectors and the game play became stable.

You could temporary solder the wires to the back side of the track ball connectors and if your problem go away you can order up some new connectors and put them in later.
 
You piggy backed the Ic on top of the old one. If the Old chip blew open than piggy backing is not a problem. If the Input to the chip shorted out than Piggy backing a chip will not solve your problem..

which 3 chips did you replace?

according to you..
"Tested the board with a known good tracball - was getting direction only one way; kinda down and to the left."

That sounds like E/f10 Or E/f11 mc14584B might be the issue.
 
You piggy backed the Ic on top of the old one. If the Old chip blew open than piggy backing is not a problem. If the Input to the chip shorted out than Piggy backing a chip will not solve your problem..

which 3 chips did you replace?

according to you..
"Tested the board with a known good tracball - was getting direction only one way; kinda down and to the left."

That sounds like E/f10 Or E/f11 mc14584B might be the issue.

Piggybacked the D/E11, D11, C11 and B11 - so four of 'em.

The boardset did that on someone else's machine but it's just a dead trackball on mine even with the trackball is fine with the other boardset.
 
So let me get this straight in my fuzzy brain.
You replace all those chips circled in red but not the two chip circle in blue.
 

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Well the chips I circled in blue are part of the circuit that will give you a nice clean signal. Basically cleans up the signal that comes from the track ball to the board.

If you have a scope you can do a signal compare from one machine to another and track down which part is causing you issues. It worth a look see.

If your getting a nice clean signal I would start looking at at where the steer clk signal is coming from.
 
Well the chips I circled in blue are part of the circuit that will give you a nice clean signal. Basically cleans up the signal that comes from the track ball to the board.

If you have a scope you can do a signal compare from one machine to another and track down which part is causing you issues. It worth a look see.

If your getting a nice clean signal I would start looking at at where the steer clk signal is coming from.

No scope, just a multimeter here.
 
Too bad your not closer I show you how to use a scope and reduce the amount of soldering and bench time. I might even have a few of those chips kicking around.
 
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