MiSTer FPGA (computer/console/arcade hardware simulation)

Discussion in 'Retro & Arcade' started by elvis, Oct 14, 2018.

  1. MUTMAN

    MUTMAN Member

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    I changed my video sync mode to 2 and no audio over hdmi when i first set it up. Been rock solid on my lcd for the arcade cores. I havent (yet) setup my old pc crt monitor to see how that looks.
    But holidays in two weeks is looking like a lot of MiSTer mucking around, and looking forward to a couple of computer and console cores too (C64 and MegaDrive in particular)

    I haven't had any time with my MiSTer this weekend, but did see a sheet the other day that might help clear up if a video modes will work or cause issues
    https://docs.google.com/spreadsheets/d/1-Le6cJ0Fzxgo3pglolequL6Fq1WynjaPWTT_jkZlBbI/edit?usp=sharing
     
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  2. Jumpingmanjim

    Jumpingmanjim Member

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    What's the state of Neo Geo support on this?
     
  3. OP
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    elvis

    elvis Old school old fool

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    Steadily getting there. Literal update overnight from the dev:
    https://twitter.com/furrtek/status/1112351731034263552

    The Neo Geo is an extremely complex beast, mostly to do with how it addresses those enormous cartridge ROMs and RAM. Squeezing that into limited FPGA space with memory speeds around 160MHz is very tricky. Not a feat for a mere mortal.

    I'm confident we'll see something stable by the end of the calendar year. Right now there are alpha builds doing the rounds that some folks have test access to, but I'm happy to wait for a public release.
     
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  4. Jumpingmanjim

    Jumpingmanjim Member

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    Furrtek really is a genius.
     
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  5. flain

    flain Member

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    Indeed, one of the crazy things is that some of the work he put into his FPGA implementation is based off images of decapped chips :)
     
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    elvis

    elvis Old school old fool

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    Experienced retro hardware hacker and programmer Chris Covell wrote a PC Engine program to measure input lag (with the help of an oscilloscope).

    https://twitter.com/covell_chris/status/1112872225290383360

    After removing considerations for CMOS processing, the results are:

    Real hardware: ~1 microsecond
    MiSTer with a USB controller: ~550 microseconds

    Despite the huge difference, MiSTer still clocks in at well under 1 millisecond (a whole frame is roughly 16 milliseconds). So the ARM+USB overhead is worse than real hardware, but still very acceptable at less than 2% of one frame (although Chris mentions that it does vary, and get worse on occasion).

    Work continues on a GPIO-connected low latency input board that will take real gamepads and push input pudding back into the FPGA core. So that's exciting for absolute purists.
     
    Last edited: Apr 2, 2019
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  7. flain

    flain Member

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    Interestingly you can actually recompile the kernel with a higher usb polling rate (there's a couple of .c files to edit) would be interesting to compare the difference.

    There is also this https://www.retrorgb.com/mister-ll-cool-joy-ultra-low-latency-controller-board-update.html but Ash would need to update the cores for it to work (which he is totally capable of based on his previous FPGA work).

    All that said - 550 microseconds isn't humanly possible to notice anyway :)
     
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    elvis

    elvis Old school old fool

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    Not as a raw number, no. But the concern is if the polling happened late in the frame, and pushed the action or intended processing to the next frame.

    Ultimately the goal is to have MiSTer act like real hardware always, and not have input delays even "occasionally".
     
    Last edited: Apr 3, 2019
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    elvis

    elvis Old school old fool

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  10. nimmers

    nimmers Member

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    It's happening!

     
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  11. OP
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    elvis

    elvis Old school old fool

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    Bloody hell, I'd build a whole new cabinet with a second MiSTer setup just for that!
     
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  12. nimmers

    nimmers Member

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    Same hardware runs ESP.Ra.De too!
     
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    elvis

    elvis Old school old fool

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    Dangun Feveron and Guwange, both of which I adore.
     
  14. darknebula

    darknebula Member

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    Holy smokes that looks good
     
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    elvis

    elvis Old school old fool

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    DoDonPachi is one of those arcade games where the analogue modeline is quite wide. I'm pretty sure the actual pixel count is 320x240, but if you try to display the real hardware modeline on a regular TV, the front porch / back porch are short, and you get a lot of cropping.

    Easy to fix on an arcade monitor where you just dial in the width, but impossible to fix on most TVs.

    Obviously scalers for LCD users make this a non-issue. But, it's time for me to roll out my TV modded with Jomac universal arcade chassis. It sits in one of those old square wooden box frames, and makes for very nice vertical arcade monitor.
     
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  16. Vanne

    Vanne Member

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    Looks like ill be waiting till next month to order the Mister boards.. Scrapping the barrel this month with interviews and getting to said interviews.. :(
     
  17. MUTMAN

    MUTMAN Member

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    Just makes the games more retro ;)

    Good Luck on the job front mate :)
     
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  18. self_slaughter

    self_slaughter Member

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    My works pretty hit and miss, but the place I was working at today asked if I could do 3 weeks of solid work.

    Once I pay back the oldies for bailing me out on a blown gearbox, I think a mister might be on the cards.

    Should work out easier than trying to get the pc hooked up to the old crt tv and use a bootload less electricity doing it. (assuming i turn the damn pc off) :p
     
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    elvis

    elvis Old school old fool

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    Sometimes small changelogs carry a lot of weight.

     
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  20. darknebula

    darknebula Member

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    I know what my missus will be buying me for my birthday in june
     
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