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About emerson

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    Northeast Ohio
  • Interests
    laserdiscs, old computers, old and somewhat new video games

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  1. Yes, just make sure you do not exceed the drive/source current of the inverter. Sometimes for line drivers the datasheet will make it easy and explicitly state how many gates the output can drive.
  2. The mouser link is the breadboard compatible module I use. The datasheet is for the chip itself. That was a bit confusing so I apologize.
  3. I knew there was an older version of the 16550 but couldn't think iof it. I'm glad you found it. I'm not totally sure how the MAX232 does it either but I can verify that they work. Some kind of charge pump oscillator? This may detract from a retro build but this FTDI module is nice. It offers full 9 pin serial support over USB. It supports RS232, RS422 and RS485. I started using it a few months ago and I like it so far. http://www.ftdichip.com/Support/Documents/DataSheets/ICs/DS_FT231X.pdf https://www.mouser.com/ProductDetail/FTDI/LC231X/?qs=Mv7BduZupUhUgQqAlkLw8A%3D%3D
  4. What about something like the 16450 or the 16550? I'm sure the people over at VCF could scare some up for you. Or try and hunt down some RS232 ISA cards... As for a DIY glue logic solution, that could get tough. You would need to recognize the 150% pulse width of the start bit to initiate your receiver and counter, then count 8 units of time (depending on your baud rate) and shift the data into a buffer on each count. The stop bit could clock the buffered data onto your parallel bus, or the data is shifted onto your bus and the stop bit clocks it into the receive register. Remember that RS232 has both positive and negative voltages so some type of level conversion as well as dual rail power supply is required.
  5. The idea was a skateboarding game and the SNES controller would mimic the PS1 controller layout used for the tony hawk games. I have some other games to finish first though.
  6. Yeah, I had to make that disclaimer since I just whipped the circuit up while I was at work, came home and drew it in kicad. The rom is designed for full SNES controller support, so yes the extra buttons work correctly. You can try it out with fceux as that emulator has SNES controller support. The rom has been tested on a real NES and it works. It would allow you to visualize what buttons the SNES would see from the modded joystick in SNES mode.
  7. nes_advantage_snes_mod.pdf Something like the schematic above should work for what you are trying to do. It's actually quite simple. All you would need to do is lift a few pins on the existing 4021 shift register, piggyback a second 4021 on top of it and run some jumper some wires. If you cut the traces around the 1/2 player switch you can use that as the DPDT and switch between NES and SNES modes. You may not need to remove the A and B resistors, just cut the traces at the right spot. The resistor tied to U2 D7 is still required. You will want to tie U2 D4-D6 high to represent unpressed X, L, and R buttons, and tie U2 D0-D3 low to identify this as an SNES controller. This circuit has not been tested and you are doing this mod at your own risk. If you would like it done but don't have the means, shoot me a pm. This is a rom I wrote that tests SNES controllers on the NES. You could use this to determine which button presses the SNES would see and verify the modded joystick works as intended. http://www.romhacking.net/homebrew/136/
  8. DTV is Digital TeleVision and CATV is CAble TeleVision. You want CATV as this implies analog video. If there is an option for ANTenna you want that instead. If you haven't yet, you will need to rescan your channels with the console turned on and connected. If you tried that and still can't get past ch69 then I suggest trying the cables suggested by Steven in post #4. Also, double check that the center conductor of the coax cable is not shorted to the new connector and that the new connector is making good contact with the coax shield wires.
  9. Bluejay gives the channels at the end of post #5. You may have to rescan your channels with the console turned on and connected to the rf input.
  10. If you check the electrical isle at your local big box hardware store they might have some as well.
  11. Yes that is the chip I was referring to. The bootgod link I posted above has the part number I was looking for though, the 74ls377.
  12. Now that I'm not at work I can dig a little deeper... I saw a few listings on ebay that had similar issues. One of them looked like it was reading sprite graphics okay but background graphics were all screwed up. Others would load the start screen then go black like your situation. As INTVCruise suggested, it seems rather common for these to fail. That smaller chip is a 74ls377, an octal flip flop. The game has 32KB of both PRG and CHR ROM. The NES can see 32KB of PRG and 8KB of CHR at a time, so the '377 is likely bankswitching the CHR ROM and not the PRG as I assumed before. The fact that you can hear music but get no picture also points to this. My previous guesses still stand. Either the '377 is bad, the CHR ROM is corrupt, or the PRG ROM is corrupt and not performing the bankswitch correctly. Here is some further reading: http://bootgod.dyndns.org:7777/profile.php?id=1159 https://wiki.nesdev.com/w/index.php/Color_Dreams https://www.ti.com/lit/ds/sdls167/sdls167.pdf?ts=1611960678989&ref_url=https%3A%2F%2Fwww.google.com%2F
  13. It's possible the lock-out disable circuitry in the cartridge does not work with the revision nes motherboard, but the fact that it initially boots may prove me wrong. The fact that it boots then stops working is interesting... That may imply corrupt ROM chips, or that chip above the PRG ROM went bad. What is the part number on that smaller chip? It is likely serving as a discrete mapper for bank switching the PRG ROM. A simple thing to try would be to reflow all the solder joints.
  14. That description unfortunately doesn't help much. Would you care to show some pictures?
  15. emerson

    Weird Cable

    My guess is an adapter for Apple II joysticks.
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