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About TheProgrammerIncarnate

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    Space Invader
  1. More resistance = longer capacitor charge = lower paddles. I'm betting the player capacitors are old, maybe you could replace them.
  2. The AY-3-8500 is now running on a FPGA! https://nerdstuffbycole.blogspot.com/2019/07/playable-emulation-and-more.html
  3. The ICs in the console should just be small/medium scale integration glue logic chips, while the cart contains a (single) much more complex chip. One of these has been decapped here. I need to know are how the pins of the chip inside the cart are connected to the internal circuitry, so pictures of both sides of the cart's PCB would be helpful. Ok, now for the mod, it's a good idea to experiment with alligator clips & a breadboard until you know exactly what circuitry it needs. Clip wires to the trace going into the connector (the one on the mainboard that leads to the modulator), as well as to ground and voltage source (the battery compartment's terminals are the easiest spots to connect to.) For amplification, all you should need is a NPN transistor with the collector connected to +X volts (through a resistor in the 100-1K range which throttles it.) The base should be connected to the video signal from the console, and the emitter should be connected to the TV through a composite cable. The cable's ground also needs to be connected to the console's ground. This is a "quick and dirty" mod as it may need biasing & impedance matching to get a better picture (hence using jumper wires before doing anything permanent.) I did a similar mod recently with the Telstar Combat, and it looked great on a cheap digital TV, though somewhat lacking on my old analog tube, so a TV's electronics may be able to compensate. If it looks bad on the TV you use, or you want to use it on multiple TVs, then you may want to improve it. Anyway thanks for the pictures, they should be good enough to figure out the internal workings, at least when the pictures re-appear. The forum update made them vanish ;(
  4. If the modulator has an RCA jack going in and another going out, you should be able to unplug the output cable from the modulator, and the input cable from the motherboard, then directly connect the output cable to the motherboard. That may do it, unless it needs amplification. Oh, and while you have it open, could you take good pictures of the front/back the accessible PCBs? I'm going to (eventually) emulate the 7600-series chips (which are in the carts) and need to know what the inside of the console looks like and what glue logic ICs it uses.
  5. Glad I could help. I'm getting one of Atari's pong systems sometime soon to melt in acid (for emulation.) Before that I'll try to figure out how to composite mod it and send the audio to the TV.
  6. It might be an internal one if that's the case Hmm, I wonder why that was there in the first place. Its DC so it doesn't seem necessary Anyway, according to the schematic, capacitor C14 is your most likely culprit. Do you have a soldering kit available?
  7. I have no idea what the test points are for, you'd have to see where the traces go. I did a little searching for your no-start + no-score issue, the person in this thread fixed his system by replacing the capacitor and pullup resistor in the "start game" switch circuit. Its much more likely to be the capacitor than the resistor, so just follow the non-ground side of the switch to locate it for replacement.
  8. It could be, as you said, something involving the start game switch. If it's not that, then its probably an internal problem with the game chip, which can only be replaced, not repaired. Does the gameplay look completely normal except for the lack of an increasing score, also have you ever ran it with batteries instead of the AC supply? Regarding audio, I could probably help you figure out how to output the sound over a RCA cable given pictures of the circuit board, although putting it into the modulator is a little more difficult.
  9. I'm trying to get samples of all the different ICs inside 1st generation consoles. Working systems are fine, but I'd rather scrap a junk system than junk a good one. You can keep the shell, all I need is the chips and pics of the PCB. If you have a system you're willing to send, tell what it is so we can figure out what chip it has in it.
  10. If you decide the chip is beyond repair, I could still use it for emulation. Like you I would prefer to use a non-functional one
  11. Here's another post. This ones about the AY-3-8606 "Wipeout" chip, which Mikebloke provided a video of above.
  12. Cool, I'm working on old chip -> FPGA conversion. Do you have a list of ones that could use replacements (other than the POKEY, TIA, GTIA, CTIA, and FREDDIE)?
  13. Hmm, the xc95288 is a larger part, and also obsolete. I'm fairly confident that an entire 1-core POKEY could fit on a iCE40LP8K with room to spare, those cost a mere 7$ (less in bulk.) I think POKEY uses capacitor-timing polling (all digital) instead of an ADC and the DAC could be emulated by high-speed PWM. So all you would need would be the FPGA, the EEPROM, and some voltage converters plus the PCB to make a pin-compatible replacement. It wouldn't be dirt cheap, but it might be less expensive than the shrinking supply of real POKEYs. For emulation accuracy the circuit description could be extracted from the decapped images.
  14. What do you guys think of the FPGA recreation of the POKEY? The code probably could use some improvement, but a modern FPGA could serve as a viable replacement.
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