Quantcast

Page 2 of 2 FirstFirst 12
Results 16 to 29 of 29

Thread: 32X Video Combination chip

  1. #16
    Outrunner
    Join Date
    Feb 2010
    Age
    30
    Posts
    538
    Rep Power
    14

    Default

    Well f me.

    I had the Model 1 port reversed. The 32X works fine. Lol. I'm so pissed off, yet, happy at the same time. I later recognized that Jorge said that the Gamesx site had it backwards. I assumed it wasn't because the MD2 on that same page isn't backwards.

    Well I'm ashamed. Thought I knew all this shit about electronics, and I can't even plug in a 32X. lol. Thanks guys, and thanks for staying persistent otherwise I would be replacing that chip right now.

    Quote Originally Posted by Jorge Nuno View Post
    Solder between the blue dot and the purple dot = short circuit.

    I meant replacing a chip with a little board containing the 2 separate ICs, not a drop-in replacement.

    Please do a continuity test on the 315-5788 pin 23 with the 315-5313 pin 42 and with your sync wire
    Yeah I know what you meant, Get a video encoder, and a 5x 2-1 multiplexer and use wire to solder them to the board correctly while they themselves sit on a different board.

    I would still like to reverse engineer some of the 32X. It just something that interests me. What's the chance of building a 32X clone?

  2. #17
    Outrunner
    Join Date
    Jul 2009
    Location
    Azeitão - PT
    Age
    34
    Posts
    723
    Rep Power
    15

    Default

    Quote Originally Posted by Xeniczone View Post
    Well f me.

    I had the Model 1 port reversed. The 32X works fine. Lol. I'm so pissed off, yet, happy at the same time. I later recognized that Jorge said that the Gamesx site had it backwards. I assumed it wasn't because the MD2 on that same page isn't backwards.

    Well I'm ashamed. Thought I knew all this shit about electronics, and I can't even plug in a 32X. lol. Thanks guys, and thanks for staying persistent otherwise I would be replacing that chip right now.



    Yeah I know what you meant, Get a video encoder, and a 5x 2-1 multiplexer and use wire to solder them to the board correctly while they themselves sit on a different board.
    Hah, so its all good now?


    Quote Originally Posted by Xeniczone View Post
    I would still like to reverse engineer some of the 32X. It just something that interests me. What's the chance of building a 32X clone?
    None / Really low... the only thing we have is a block diagram, and 5 out of 10 main-chips are SEGA custom or rebranded parts (and the SH-2's (HD6417095-F28) datasheet is nowhere to be found).
    We have don't even have pinouts for any of them, so meh

  3. #18
    Outrunner
    Join Date
    Feb 2010
    Age
    30
    Posts
    538
    Rep Power
    14

    Default

    Quote Originally Posted by Jorge Nuno View Post
    Hah, so its all good now?
    Yeah everything is great!




    None / Really low... the only thing we have is a block diagram, and 5 out of 10 main-chips are SEGA custom or rebranded parts (and the SH-2's (HD6417095-F28) datasheet is nowhere to be found).
    We have don't even have pinouts for any of them, so meh
    Yeah, I started doing research into it a while ago, and couldn't find much on it. So I tried looking into doing hardware emulation on it, similar to the modern MegaDrives clones, but it seems that even in PC emulation the power needed to emulate the 32X is ungodly. 32X-PC Emulators required a minimum of a 750MHz P3 to run while Genesis-PC Emulators require as low as a 60MHz 486. So I assumed this translated into the same meaning for the hardware emulation. The power required is too much. Plus I wouldn't know where to start to build a hardware emulation.

    Why would a datasheet be needed for the 32X SH-2's, wouldn't a pinout of it be sufficient? Modern SH-2s I believe are twice the speed as the ones used in the 32X, but they should be the same procession units correct?

  4. #19
    Outrunner
    Join Date
    Jul 2009
    Location
    Azeitão - PT
    Age
    34
    Posts
    723
    Rep Power
    15

    Default

    You can't just build a functional-equivalent model of the 32x, because there are signals and timing requirements that must be just like the originals in order to function correctly in conjuction with the megadrive and the cart hardware.

    Also: we don't even know the function of some (around 2 or 3) of the cart slot signals used by the 32x.

    The CPU processing units would be similar, but there might be some serious differences, like different opcodes, execution times, interrupts or peripherals.
    Only on really rare occasions you can get a pinout without a datasheet, like reverse engineer the board where the chip is used (I did this for the 315-5433 pinout, it was a modest challenge). The problem of reversing the 32x board is that it is a multilayer board.

  5. #20
    Road Rasher
    Join Date
    Apr 2010
    Posts
    255
    Rep Power
    14

    Default

    Just a quick question guys...

    from the output of the MD to the 32x, are we supposed to connect every wire ie, blue to blue, green to green etc...

    I'm not sure if I need 5v, mono audio and component/sync.

    also, what is better for sync? comp or sync?

    Also how is the sound supposed to be mixed in with the SegaCD?

    Regards

    Brendan

  6. #21
    YM3438 Master! ESWAT Veteran evildragon's Avatar
    Join Date
    Oct 2006
    Location
    Oviedo, FL
    Age
    34
    Posts
    7,456
    Rep Power
    64

    Default

    You want composite sync.. It doesn't care about NTSC composite video though..

    Audio lines just get forwarded to the back. So if you use a mono AV cable, forward the mono av pin.

    If you use a model 1 genesis, just grab it from the headphone jack.
    Customized Sega Genesis Model 1 - VA3. Energy efficient with buck converters instead of LM7805's.


  7. #22
    Road Rasher
    Join Date
    Apr 2010
    Posts
    255
    Rep Power
    14

    Default

    So lemmie get this straight, I will pull composite video from MD av out to sync 32x av in?

    I want to use stereo. at the moment i am using a MD2... I will make seperate audio seperatly to make spdif... but I was just wanting to find out how you are supposed to hook all the sound connections together MD > MCD > 32x?

  8. #23
    YM3438 Master! ESWAT Veteran evildragon's Avatar
    Join Date
    Oct 2006
    Location
    Oviedo, FL
    Age
    34
    Posts
    7,456
    Rep Power
    64

    Default

    No, I didn't say use Composite video. I said use Composite Sync.
    Customized Sega Genesis Model 1 - VA3. Energy efficient with buck converters instead of LM7805's.


  9. #24
    Road Rasher
    Join Date
    Apr 2010
    Posts
    255
    Rep Power
    14

    Default

    so for 32x av output, unlike the MD, should composite sync be used over composite video for sync ing? Or will it have the same performance?

  10. #25
    YM3438 Master! ESWAT Veteran evildragon's Avatar
    Join Date
    Oct 2006
    Location
    Oviedo, FL
    Age
    34
    Posts
    7,456
    Rep Power
    64

    Default

    Ok, lets try this again..

    Genesis to 32X: Composite Sync, R, G, B, Ground. Audio just gets forwarded to the out ports.

    32X will generate it's own Composite Video signal, and also RGB output with Composite Sync...
    Customized Sega Genesis Model 1 - VA3. Energy efficient with buck converters instead of LM7805's.


  11. #26
    Hero of Algol kool kitty89's Avatar
    Join Date
    Mar 2009
    Location
    San Jose, CA
    Age
    31
    Posts
    9,725
    Rep Power
    65

    Default

    Composite sync has nothing to do with composite video, all it means is that it's the video sync signa; with both Horizontal and vertical sync combined rather than separate H/V sync or sync combined with one of the color signals. (like sync on green, component or s-video with sync on luma or composite video with sync combined with chroma+luma)
    6 days older than SEGA Genesis
    -------------
    Quote Originally Posted by evilevoix View Post
    Dude it’s the bios that marries the 16 bit and the 8 bit that makes it 24 bit. If SNK released their double speed bios revision SNK would have had the world’s first 48 bit machine, IDK how you keep ignoring this.
    Quote Originally Posted by evilevoix View Post
    the PCE, that system has no extra silicone for music, how many resources are used to make music and it has less sprites than the MD on screen at once but a larger sprite area?

  12. #27
    Road Rasher
    Join Date
    Apr 2010
    Posts
    255
    Rep Power
    14

    Default

    ah ok... so audio is form 32x (through cart slot) > MD > MCD > speakers.

    video doesn't need comp vid for sync.

    so just an off topic question: how come comp vid is used (looks cleaner) instead of comp sync?

  13. #28

    Default

    Hi,

    I recently bought a 32x which ended up being broke due to a corroded ribbon cable. i got another one and found when using it a bad picture is displayed similar to the images in this thread except the colors and definition are perfect.

    i have a mega drive 1 hdg model on a mega cd 2 with a 32x on top. (all pal machines)

    The mega drive one works great on rgb. i tried wiring the sync out of the mega drive to the composite in on the 32x and nothing changed, then i tried sync out to sync in and still no change, i then tried changing the sync pin in the mega drive to right off the encoder pin with a cap and resistor hoping for a cleaner signal, again no change at all.

    http://www.mmmonkey.co.uk/console/sega/md-sync.htm


    as the md seems to work on its own fine i assume the problem is with the 32x or the cables. what should i check on the 32x to ensure its ok?

    then wiring. Do i do r g b and sync ONLY on the patch lead and then the sync out of the 32x to the scart pin 20, or should pin 20 be hooked up to the composite out of the 32x? i dont need any audio or composite unless its needed to get rgb to work.

    its all confusing and upsetting!

  14. #29
    Hedgehog-in-Training Hedgehog-in-Training
    Join Date
    Jul 2020
    Posts
    6
    Rep Power
    0

    Default

    Interesting thread....
    I have currently a problem on a 32x and I'm pretty sure it comes from the 315-5788 (Video Mix). I have tested my 32X with 2 different Megadrives (MD1 and MD2) and with several different cables and I have always the same problem : the screen color is red only , no blue nor green signals. (I have tried it on my TV and my OSSC)
    I have made some continuity test arround the 315-5788, the video input and output (DIN9) and everything looks fine.
    Finally, I have tested the 315-5788 with a logic probe and it appeared there is no signal on the Blue Out and Green Out (pin 27 and 28) but signals on RGB In 1 and 2 and Red Out are good (pins 4 o 9 and pin 29).

    Now, I'm searching for a way to replace this part of the 315-5788 (only the RGB part, I don't need the Sync part as I'm using the CSYNC from the MD).
    I was told about a LT1675CNG (with a LM2776 for a -5V) which looks fine to me but I would like to know what do you think about that ? I was also thinking about a CD4053 but it doesn't really look dedicated to RGB signal (in fact, I don't really know...)

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •