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TheProgrammerIncarnate

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Everything posted by TheProgrammerIncarnate

  1. TheProgrammerIncarnate
    I'd add three categories to the list above: TTL&analog based systems, games centered entirely around a unique ASIC, and ones that rare and/or expensive have yet to be dumped. TTL/analog systems (e.g PONG, Death Race, Monaco GP) have historically been difficult since MAME/MESS has been based around a system's CPU, which causes problems for CPUless systems. DICE managed to emulate several of these, but it was last updated in 2014. Thankfully a recent reworking of MAME means it can now emulate TTL games, the drivers just have to be written. ASICs are in almost every system (e.g. graphics chips, sound chips, memory mapping chips) most are fairly well documented though. For the ones that aren't, they may have to be decapped (AY-3-86XX series, Color TV Games, Telstar Arcade) and reverse-engineered, which has only had recent progress. Other techniques include extensively probing the pins with a logic analyzer either alone or in the system (which is being used to further understanding of the SNES PPU chips), or reverse-engineering behavior based on disassembled dumps (which is being used on the undocumented XaviX ISA) The last category is fairly self-explanatory, so keep your eyes out for prototypes.
  2. TheProgrammerIncarnate
    Rest In Peace friend. Now you join Atari in heaven...
  3. TheProgrammerIncarnate
    One lost "console" always been interested in is AY-3-8750. It's not a console per say, but an unreleased member of the 8600/8700 chip series, which powered PC50x pong systems. Only clue I've found of its existence was this page in the GIMINI catalog.
  4. TheProgrammerIncarnate
    I did a rudimentary mod on my Sears breakaway about a year ago. There should be a large metal box just to the right of the speaker hole in the PCB. This is the RF modulator. The output side connects to a composite jack going outside the case, and the input side connects to a trace on the PCB. That trace is your unmodulated video signal. I did a quick-n-dirty mod by directly soldering a RCA cable to that trace. Output looked terrible on an analog TV, but wonderful on a digital one (I'm guessing the digital TV could better deal with an unamplified/impedance-matched signal.) Still need to figure out how to do a proper mod sometime.
  5. TheProgrammerIncarnate
    The controls are a little weird, first off the tank takes time get up to speed or move at all (part of the game logic, not controls.) Second, pressing one stick at a time will not do anything. Two sticks forward=forward Two sticks back=brake/backwards One stick forward + one stick back=turn If at least one stick is in the resting position, then your tank will move from its existing momentum, which does not decay unless you hit the brake. See if that works, if you're still having problems you can try opening the console up and cleaning the contacts. They're in little removable black boxes underneath the sticks.
  6. TheProgrammerIncarnate
    Here's a picture of the underside, which has labels. Regarding rotation of the plugs: one side is flat while the other juts out. The side that juts out is supposed to face away from the camera in your image, so it latches with the socket.
  7. TheProgrammerIncarnate
    Thanks! It is kinda amazing how little info some of these chips have. Like the Submarine chip, I only found one video besides yours of it online! Thanks for reminding me of that! I just added a link on the wiki page.
  8. TheProgrammerIncarnate
    The AY-3-8500 now has a MiSTer core based on die photos!! I've also been working on other things, such as highlighting chips automagically with a soft AI. https://nerdstuffbycole.blogspot.com/2020/01/end-of-year-update.html
  9. TheProgrammerIncarnate
    Power it up, then press the reset button a few times. If no sound comes out then the issue is most likely with the custom IC inside it. It doesn't have a ROM or program, rather discrete flip-flops, counters, and latches crammed into a single chip.
  10. TheProgrammerIncarnate
    As the MPS7600-001 has been decapped, so it can and will be eventually converted into a FPGA, which could be put into a repro cart #1. All other carts use different variants of the 7600, which have not been decapped yet. I'm not confident that a reproduction would fix the bugs you've described, as they're most likely exist in the design and not from a damage to the actual chip.
  11. TheProgrammerIncarnate
    Yeah, I can confirm from looking at the die that it's a custom micro-controller with a ROM on board. Interestingly it's not 512 bytes, it's actually 256 13-bit words of programming, plus a bunch of large lookup tables that hold other data. I'm not entirely sure about that as it's not been simulated though. Also, there was a 5th and 6th cartridge advertised? I've never heard of that! Do you know where one can find more information about those?
  12. TheProgrammerIncarnate
    The MARIA-related thread was last bumped in 2010 while this one was more recently active so I posted it here. The GTIA, MARIA, TIA are all in the same vein of Atari custom graphics chips. No biggie. I heard somewhere that Curt was hesitant to release files because he gave them to someone in the past who used them in something closed in proprietary. No idea if that is true or not. Anyway, he shared them with me and Alan S. (not on AA forums) because Alan was wanting to improve the 7800 core for the MiSTer project (an open FPGA emulation system) and because I've been working on automatically turning layout information into schematics/verilog in my own project. I agree 100% that they should be freely available, but I'll wait till Curt decides that they should be. Perhaps a GPL-esque license would ensure they are only used in open projects.
  13. TheProgrammerIncarnate
    Curt just released the schematics here. He also shared the GDS files with me in hope that I could help convert them to verilog. Unfortunately I've been unable to open them as they're an older format of GDSII files.
  14. TheProgrammerIncarnate
    Got the AY-3-8605 "Sea Battle" chip in a simulation and generating screenshots. I don't think there's been any form of emulation prior to this. https://nerdstuffbycole.blogspot.com/2019/10/shooter-game-in-silicon-inside-ay-3.html
  15. TheProgrammerIncarnate
    Hmm... The Odyssey 4000 apparently uses a AY-3-8600 game chip, with color from a AY-3-8615 chip. According to the databook (page 486) video out on the 8615 is pin #5, you tested this one, right? Besides that there are a few traces between the two chips, and the clock signal circuitry (if the game plays then the clock circuitry should be fine.) Also, what thread did you base your composite mod on? It may be that the 8615's outputs need amplification or adjustment before the TV can process them.
  16. TheProgrammerIncarnate
    Interesting observation! Perhaps one of the pins on the 10 game chip served to downgrade it to a regular Super Pong chip. So they could sell Super Pong & Super Pong 10 systems with the one chip once it came out.
  17. TheProgrammerIncarnate
    Here's the picture of the upper-right corner. I think I labeled all hidden/obscured parts. Also, the speakers are 0.2W, 8 Ohm for the record. Unfortunately I'm going to be away from home again so I won't be able to properly inspect those pots or inductors. Just mark them with "untested" for the time being. Also, I'm going to store the schematics in my 1st gen game system REing git repo, you won't mind as long as I credit you?
  18. TheProgrammerIncarnate
    Ok I confirmed the values of everything except stuff in the far upper-right. There's a close-up of that region, so I'll mark that picture instead as this one is blurry and has things in the way. A few things I wasn't able to confirm/find out values on: the two inducters/coils inside the modulator, the two inductors to the left of the power switch, and "L1" which appears to be a ferrite choke. None of these had values on or near them. Two of the dark brown film capacitors & a transistor inside the modulator were too tightly packed for me to read their values. The transistor is probably a standard or video-specific NPN, while the capacitors are probably "39" (nanofarads?) like all of the others of that type. Lastly the two blue pots don't have values on them and appear to have been set at the factory, as they've been glued in place. I also found the manual in slydc's archive, cleaned the controllers, and took some notes on the gameplay. That'll be useful for whenever I start looking at the AY-3-8700's die.
  19. TheProgrammerIncarnate
    Second picture? There's only one up there. I'll get back to you on the trim pot.
  20. TheProgrammerIncarnate
    Here's your picture with the values filled in. I just noticed that all of the green capacitors (except the small one in the upper right) are 0.1uF. Sorry for the late reply, I've been busy.
  21. TheProgrammerIncarnate
    The components are currently on a breadboard, so I used an alligator clip connected to the unmodulated video (blue circle), along with a pair connected to power/ground lines. I forgot to mention it earlier, but a decoupling capacitor should be added to the mod. Without it, the brightness fluctuates whenever the sounds play.
  22. TheProgrammerIncarnate
    Ok I messed around with the composite mod again and here's the results. I used a 470+100ohm voltage divider, plus a 100ohm resistor to match impedance (75ohm might be better, but I don't have any.) Schematic is below. On the digital TV it looks great, except for some noticeable vertical lines which are based on the clock frequency. On the CRT TV, the black components (right tank + mines) and grey background are hard to tell apart, the white areas also are not maximum brightness. But when I set the CRT's brightness to 100 (instead of 50) it looks perfect. Which is making wonder if the composite mod is good but the TV isn't.
  23. TheProgrammerIncarnate
    R71 is 100 ohms The capacitor under C50 is C38, I can't see anything except 33/16 & "Tracon" on them. They look like pre-speaker filters, which should limit their possible values. R7 is correct The transistor near Q3 is Q4, across from it is Q5 Q5 says "1702M P731" on it, while Q3 & Q4 say "MPS A13" Google says the 1702M is an audio transistor which would make sense. The mylar capacitors only say "1.50V" on them, so I'll have to test them along with the Tracon ones
  24. TheProgrammerIncarnate
    Here I added some more pictures to the ones I already took: https://drive.google.com/drive/folders/1wT2uEGUd0Weu8t7w5Pnv5nfFAgAe3Tmx?usp=sharing Just tell me which components you can't see properly and I'll look at them closer
  25. TheProgrammerIncarnate
    Huh, I wonder if someone tried repairing this unit before... Anyway, I'm back home now and can look at my Combat! unit + take pictures if that helps either of you.
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