"Let's make GD ROM emulation happen" Facebook group.

Discussion in 'Sega Dreamcast Development and Research' started by sonicdude10, Jun 18, 2012.

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  1. Melchior

    Melchior Rapidly Rising Member

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    You are making big strides!

    What about a plain'old DC-Serial TTY Debugger cable? less fonts, more bit-twiddling, less corruption (and its bi-directional!)

    http://mc.pp.se/dc/serifc.html

    There are variations of that design that use the PL-2303 chip that are up to 1mbs...
     
  2. sonicdude10

    sonicdude10 So long AG and thanks for all the fish!

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    The problem with that is the same as with the serial SD adapter. Too slow to work with lotsa games. 1 Mb a second aint gonna cut it with some games.
     
  3. Calpis

    Calpis Champion of the Forum

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    Wha? 1 Mb = 1 megabit = slower than a 1X CDROM. Even full-speed USB with a ~9 megabit/s payload doesn't cut it for game streaming, you need high-speed USB.
     
  4. cybdyn

    cybdyn Embedded developer (MCU & FPGA)

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    1mb = mega byte , it uses abnormal bitrate up to 6 mb (megabod) , but you can't get such speed cause serial port of DC has limitation 115,200 kb. but it can be useful anyway to transfer data to PC to see what in your buffer after DMA'd , you need make application for PC, or maybe use Terminal porgam

    about source code for IDE or SD interface: i remind altera gives examples in vhdl or similar.
    and for DEх boards with sd slot. so you can built in to your project if figure-out how it works.


    http://www.altera.com/literature/an/an495.pdf ide controller

    http://www.altera.com/products/ip/iup/additional_functions_iup/m-eur-mmc-host.html
     
  5. Melchior

    Melchior Rapidly Rising Member

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    Did no-one read that this was for DEBUGGING?

    Also - the limit of 1mb is from the CPU's FIFO/USART - since its going to be used for controlling the IDE / uploading code / scanning memory or just poking a few bytes at a time... typed out by hand - I'd say 2400 baud is the fastest you'd really need (unless dumping the whole of system ram...)
     
  6. sonicdude10

    sonicdude10 So long AG and thanks for all the fish!

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    I didn't ever look into that. I did post earlier in this thread about using the serial port for control of the data from the GD ROM port for use with IDE/ATA storage devices.
     
  7. Calpis

    Calpis Champion of the Forum

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    ??? Are you saying 1 megabit or megabyte/mebibit or mebibyte? Use the established abbreviations.

    The DC can pump out data faster than 1 megabit as evidenced by SD adapter, but integrated RS232-USB bridges have a hard limits of 1-3 megabits due to the way they handle clock recovery by oversampling. Charge pump translators like the MAX232 are similarly constrained.

    You called it the "debugger" cable but failed to mention it should be used here for debugging and not the topic at hand -- game streaming. How is anyone to know what you're thinking? How is it relevant to game streaming?

    This discussion is suffering from the bikeshed effect.
     
  8. cybdyn

    cybdyn Embedded developer (MCU & FPGA)

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    sd spi intarface through serial is artificial. you can see what pin used for CLK. cause Store operation to any address is faster than using native Serail controller. so that why we can get more than 115 200 baud


    serial can be useful for not large amount of data, just for get status info / sending cmd's. DC hasn't any other way for such thing.
     
    Last edited: Aug 18, 2012
  9. Calpis

    Calpis Champion of the Forum

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    SPI is "bit-banged" but that's irrelevant. And no, you can get faster than 115200, the baud rate generator can go to something like 1.5 Mbit with the DC's peripheral clock.

    The DC doesn't have another way built-in (barring the modem or ethernet), but this project isn't built-in either so I don't see your point. Once you interface with the expansion bus using a FPGA you've already got a way to debug. I do believe the Dreamcast also has video which is pretty good for debugging.
     
  10. OzOnE

    OzOnE Site Supporter 2013

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    Hi, guys,

    I've tried to get a USB-to-serial adapter working with my debug app without success.
    I know the adapter is working OK, but I haven't got the DC side to work yet, even if I remove the SD card after it's loaded?

    It's probably something obvious, I know it should be working OK under KOS.

    I didn't get much done on the weekend as I was camping in a field at the Rewind 80's Festival.
    Quite a few great bands there - Grandmaster Flash, Soul2Soul, The Straits, Adam Ant, Midge Ure, Marc Almond, Roland Gift and... Mr Rickroll himself Rick Astley!!

    Tony Hadley was brilliant (jeez, that guy can still sing!). By far the best was OMD though - been waiting years to see them live and they blew everyone else out of the water. AMAZING. :very_drunk:


    Anywho, I've just posted the full "code" for the GD Debug app on SWAT's forum..

    http://www.dc-swat.ru/forum/thread-1902-post-23518.html#pid23518

    Hopefully this will generate more interest in this IDE / PATA / (SATA w/adapter) / CF / HDD thingybob.

    If anyone has a DC dev environment set up and wants to try soldering an IDE cable to their DC, please check out the diagram on the above link.
    The IDE pinout numbers "should" be OK. Obviously all the Ground connections on the IDE cable need to be grounded to the DC and any spares left unconnected.

    tbh, if this can't be made to boot GDI's then the only difference from an SD adapter would be the loading / ripping speed.
    Maybe only SWAT will know how to get a GDI to boot properly (if it's even possible)?

    OzOnE.
     
  11. runkthepunk

    runkthepunk <B>Site Supporter 2013</B><BR><B>Site Supporter 20

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    Sounds like an great eighties weekend to me!

    Hopefully DC SWAT can help you with any of your problems as those guys continually deliver seriously good work.

    cool
     
  12. cybdyn

    cybdyn Embedded developer (MCU & FPGA)

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    Last edited: Aug 31, 2012
  13. veganx

    veganx Dauntless Member

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    Great work Cybdyn! Hope you get the SD protocol working!
     
  14. Bad_Ad84

    Bad_Ad84 The Tick

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    thats not cybdyn's work.
     
  15. veganx

    veganx Dauntless Member

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    Is this from Ozone?
     
  16. CodeAsm

    CodeAsm ohci_write: Bad offset 30

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    Looking very nice :p
    is rotating the mcu 45 degrees clockwise making the traces shorter to the memory any nice idea?
    Good luck with the SD card :D
     
  17. spinksy

    spinksy Peppy Member

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    Awesome work!
     
  18. cybdyn

    cybdyn Embedded developer (MCU & FPGA)

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    it'snot my work.... i just said news.
     
  19. spinksy

    spinksy Peppy Member

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    I was saying 'Awesome work' in regards to the guy who did that(from the link you posted) and generally everybody thats putting time and effort into trying to get this to work.
     
    Last edited: Aug 31, 2012
  20. maringouin11

    maringouin11 Rising Member

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    Oh great news ! Awesome work
     
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