For anyone with knowledge of circuit diagrams/symbols. (space invaders related)

I'm trying to create a circuit for my Space Invader PCB's Power on Reset Pin.

It's a simple circuit however, I have no idea what this section (triangle symbol) and the surrounding numbers represent.

It's an inverting logic gate.

3 is the input.

2 is the output.

Not sure what the other #'s represent.

Long story short, I rewired my SI cocktail table wrong and turned it on.

After getting it wired back up right. I get a garbled screen and the start up sound loops. On the pinout sheet I have it says pin 10 on the sound board (POR) must be wired to ground or the screen can be garbled and you get sound for 10 secs or more. They also give a circuit that "better simulates" the POR. What I don't understand is the POR was hooked to ground originally on the power supply and it worked.

So what did I do. I ripped out the SI wiring harness and rigged up a Jamma adapter with a fingerboard I hacked off a Fighters History bootleg pcb. I get the same bullshit with the POR wired to ground (it's running on my nova now). I'm afraid the pcb could be toast.

SamuraiShodownSensei said:

Long story short, I rewired my SI cocktail table wrong and turned it on.

After getting it wired back up right. I get a garbled screen and the start up sound loops. On the pinout sheet I have it says pin 10 on the sound board (POR) must be wired to ground or the screen can be garbled and you get sound for 10 secs or more. They also give a circuit that "better simulates" the POR. What I don't understand is the POR was hooked to ground originally on the power supply and it worked.

So what did I do. I ripped out the SI wiring harness and rigged up a Jamma adapter with a fingerboard I hacked off a Fighters History bootleg pcb. I get the same bullshit with the POR wired to ground (it's running on my nova now). I'm afraid the pcb could be toast.

Click to expand...

Ok you didn't supply enough information, how did you rewire the board, but I am going to ASSUME the POR is controlled by the inverter which would be the triangle symbol you posted. Is the ground wire that you are running from the power supply going into this inverter. If yes when you rewired your board want was the voltage you applied to the input of the inverter. If it was 12 volts then your in trouble. Do you know a little something about digital logic? In digital logic there are only two states, 5 volts for high and 0 volts for low and nothing else so if you applied a higher voltage there could be problems. What a inverter does just for your reference is that it takes a high state voltage ( 5 volts ) and output the low state voltage ( 0 volts ) and vice versa. Long story short before you tampered with the board and with that wire having originally being wired to ground when the board was powered the POR circuit was inverting that ground low state into a high state. My guess at the problem and solution is that you burned out that inverter and a possible fix would be to replace it ( inverter are common logic gates that are easy to find or buy) But if you what to try this out you can if you want too. You stated yourself that the pinout sheet I have it says pin 10 on the sound board (POR) must be wired to ground or the screen can be garbled and you get sound for 10 secs or more. Since this is the same problem you are having that is explain on the schematic then it has to be a problem with the POR circuit so why don't you try to bypass it by running 5 volt ON THE OUTPUT of the POR circuit, remember I said even though The input of the POR circuit is at ground the output is however at 5 volts. By doing this the game should work, but I would recommend replacing that inverter. Like I said without the schematic in front of me I assume the POR circuit is controlled by the inverter.

Space Invaders requires an outside reset circuit. We sell one designed for Space Invaders and other external reset games. Please email sale@Eldoradogames.com for more information and pricing and availability.

Nightmare Tony said:

Space Invaders requires an outside reset circuit. We sell one designed for Space Invaders and other external reset games. Please email sale@Eldoradogames.com for more information and pricing and availability.

Click to expand...

Thanks, I'll keep that option in mind.

whoops, its sales@eldoradogames.com, not sale. plural