Mega Drive / Genesis hardware revisions

Discussion in 'General Sega Discussion' started by ICEknight, Apr 21, 2012.

  1. ICEknight

    ICEknight

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    I just got this brand old Japanese Mega Drive:

    [​IMG] [​IMG]

    And I was wondering which of the many versions available it could be.

    According to this guide, this would be a:
    -Mega Drive 1
    -Japanese
    -"AV Intelligent Terminal/High Grade Multipurpose Use" model
    -With "(R)" next to the SEGA logo


    And then:
    So it would be something between VA0 and VA4...

    I didn't see any "rainbow effect" as it's implied happens with models VA2 to VA5, so I guess it would be either a VA0 or VA1... or perhaps the rainbow effect isn't as noticeable on my PAL TV or something, so all I really know is that it's between VA0 and VA4. =\


    Are there any other ways than opening the console to know the motherboard revision it may host inside?

    Some things that might help tracking down the model:
    -No "RF OUT" connection, just the one for composite.
    -Controller has red paint in the A B C letters and a quite short cord.
    -RESET button isn't as blue as the controller's START, but more gray-ish.
    -I've come across some odd sound behavior in games like Revenge of Shinobi CD (v.3). When the music track "MAKE ME DANCE" is playing, the jumping sound effect (#00) seems to fuck up one of the instruments (at least when playing the level with the killer nuns, haven't checked this on the Sound Test).
    -I've also noticed some slowdown in certain games (Streets of Rage CD), that I don't remember getting in my old PAL system... but then again, PAL systems are being continously slowed down.



    By the way, is it known which official (unmodded) Mega Drives did have the best picture and sound quality of them all?
     
  2. TmEE

    TmEE

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    no japanese machine has RF-out, which doubles the hardware revisions... almost


    For MD1 there is :
    VA0, VA1, VA2, VA3 ,VA4, VA5, VA6, VA6.8, VA7

    Until VA4 there was no TMSS, VA5 has no TMSS in JP but in EU/US it has TMSS shown, any newer machine always shows TMSS.
    VA0 and VA1 are JP only, there never appeared outside Japan.
    VA2 is USA launch model
    VA4 seems to be what EU first got
    VA6.8 uses surface mounted CXA
    VA7 is MD2 in MD1 shell

    For MD2 there is :
    VA0, VA1, VA1.8, (VA2 not sure if it exsits), VA2.3, VA3, VA4

    VA2 uses toshiba ASIC and discrete YM
    VA4 uses ASIC found also in Genny3 VA0 and 1

    For Genny3 there is :
    VA0, VA1, VA2

    VA2 uses final MD ASIC also seen in Sega Pico, it also uses unified SDRAM controller and has VDP vscroll bug fixed. Nearly fully integrated.
     
  3. ReBirFh

    ReBirFh

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    Under it the sticker says HAA-2500 or HAA-2510?
    Does it have the modem connection in the back?
     
  4. Meat Miracle

    Meat Miracle

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    What is the serial number?
     
  5. ICEknight

    ICEknight

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    It has no TMSS screen so it must be VA5 or earlier, and it has the Modem port, does that narrow down the possibilities?

    I'll check the model and serial numbers next time I go to my parent's.


    EDIT:
    Wow, so the Mega Drive had a bug in the VDP up until the very last version that was released? Does it affect any official games?
     
  6. Andlabs

    Andlabs

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    Writing my own MD/Genesis sound driver :D
    Yes; a number of games are affected by the fix, Kawasaki Superbike Challenge being one of them. I don't remember the exact specifics but the bug (a well known one) is that VScroll in the first cell colulmn isn't calculated correctly. The Genesis 3 also has this fix.

    Does the Japanese After Burner II work on your MD? (I think I asked this elsewhere but eh)
     
  7. Sik

    Sik

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    being an asshole =P
    Huh, no TMSS means all games should work (region lock-out aside).
     
  8. Andlabs

    Andlabs

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    Writing my own MD/Genesis sound driver :D
    wait derp stupid me

    IIRC GerbilSoft posted information about board revisions on the wiki?
     
  9. GerbilSoft

    GerbilSoft

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    There's a few games that have workarounds for the VDP bug, so they "break" on the systems with fixed VDPs. One such game is Kawasaki Superbike Challenge:

    [​IMG] [​IMG]

    The left image is how the game should appear (on consoles with the VScroll bug). The right image is how it appears on Genesis 3 VA2 and on emulators that don't handle the bug correctly.

    Specifically, the bug is caused by incorrect handling of VScroll column "-1", which happens if the HScroll offset for a given line/tile/screen is not divisible by 16.

    The easiest way to figure out what revision MD you have is by disassembling it and checking the system board. It's printed towards the bottom.

    Sega_Mega_Drive/Board_Revisions

    Currently has scans of six board revisions:
    • MD1: VA2 (USA)
    • MD1: VA6 (USA)
    • MD1: VA6 (PAL)
    • MD2: VA1.8 (USA)
    • MD2: VA1.8 (Asia)
    • Gen3: VA2 (USA)
     
  10. Meat Miracle

    Meat Miracle

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    Easiest but not 100% accurate is to check the serial, actually.

    Though it's only accurate if 1. the sticker wasn't removed, 2. the case was not changed. And .8 subversions are not visible.
     
  11. ICEknight

    ICEknight

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    I was able to check the Serial Number today, and it's: 99N61029

    I think the second digit ("9") means it was made in 1989, but that's all I can get from that number.


    Also, if it helps, the model is HAA-2510.
     
  12. Meat Miracle

    Meat Miracle

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    Yup, indeed made in 1989, and it uses an old numbering system I have no info of. They changed to a standard format around 1990, where you could read board numbers right out of the serial. Before that, that letter had all kinds of letters in it. I'd guess VA0 or VA1 based on age alone.

    It would be cool if you could take a photo, both from the serial and if you end up disassembling the thing.
     
  13. ReBirFh

    ReBirFh

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    Sorry to interrupt but is there any interest in pictures of boards from other countries? I took pictures a few years ago of my 3 Tec Toy Mega Drives (MEGA DRIVE, MEGA DRIVE II, MEGA DRIVE III) I could upload it here or in the proper place.
     
  14. Meat Miracle

    Meat Miracle

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    There always is. Post away.
     
  15. ReBirFh

    ReBirFh

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    MEGA DRIVE (BRA - TEC TOY)

    - with Modem Port
    - IC BD M5 USA VA3
    - 837-7071

    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]


    MEGA DRIVE II (BRA - TEC TOY)

    - with Modem Port
    - IC BD M5 USA
    - 315-5402: VA5 / 315-5433: VA6

    [​IMG]
    [​IMG]
    [​IMG]
    [​IMG]

    MEGA DRIVE III (BRA - TEC TOY)

    - TE 0595 (2)
    - PCI M.D. III c/RF Rev.02

    [​IMG]
    [​IMG]
    [​IMG]


    MEGA DRIVE (CLONE?? - ASIA) <-- Not hard to find in Brazil and considered a high quality, perfect or almost perfect clone (Ace from SEGA-16 said it was a clone)

    - without modem port
    - Model Nº 1600-16
    - Serial Nº 020012169
    - MD-16M
    - T010163

    [​IMG]
    [​IMG]
    [​IMG]
     
  16. ICEknight

    ICEknight

    Researcher Researcher
    Oops, I knew I should have taken a pic of it. I might be able to, next week.


    ...So newer Serial Numbers allow to know the hardware version? I also took notes from the three PAL systems I own.

    Here's the info I got from all of them:


    (1)
    Model: HAA-2510
    SN: 99N61029
    "AV Intelligent Terminal"
    With modem port
    No RF connection
    Made in Japan
    Notes:
    -Japanese Mega Drive
    -Pack-in controller has really short cord
    -Bought at "Happy Shop"



    (2)
    Region: PAL-G
    Model: 1600-18
    SN: 40f2272G
    "High Def"
    With modem port
    Made in China
    Notes:
    -Bought in Spain when the first TMNT game on the NES was still the cool thing
    -Came with Altered Beast, as printed on the box
    -Has awesome sound quality



    (3)
    Region: PAL-G
    Model: 1601-18
    SN: 120362171
    No "High Def"
    No modem port
    Made in China
    Notes: Most likely bought in Spain, originally



    (4)
    Region: PAL-G
    Model: 1601-18
    SN: 130071623
    No "High Def"
    No modem port
    Made in China
    Notes: Most likely bought in Spain, originally.



    If I understand correctly, the last three were built in '90, '92 and '93, respectively... But I can't figure out which of those numbers is the motherboard version. =\
     
  17. dsrb

    dsrb

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    So, the Mega Drive II is actually a Mega Drive 1, and the Mega Drive III is actually a Mega Drive 2? :psyduck: I wonder what that says about the Mega Drive I
     
  18. ReBirFh

    ReBirFh

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    MEGA DRIVE (I) [BRA] and MEGA DRIVE II [BRA] are the worldwide MEGA DRIVE / GENESIS (I), TEC TOY numbered them differently as a marketing strategy, there is actually another version of MEGA DRIVE II called "Control Unit" this one doesn't have RF output and the bundle didn't include any game.

    TEC TOY used the same numbering system with the MASTER SYSTEM (I and II are I worldwide and III is II worldwide)
     
  19. Meat Miracle

    Meat Miracle

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    I'm honestly not sure. I took a few hour nosedive searching for serials, and it looks like they standardized their system mid-1990. Everything from that uses the exact same system, from Teradrive to Saturn. *

    Anything before that seems to be iffy and random though, including the Megadrive. The MD1, specifically, is weird: for 1989 models, the revision number in the serial cycles through letters. Then starting from mid-1990, it's just fixed at 0, no matter the internal hardware. I imagine they first used letters for the production week, then they switched to hardware revision, but this is just speculation unless someone drops in 100+ MD1 serials for us to analyze. I think it's time I started saving those as well.


    * except JVC X-eye and JVC V-Saturn which use Victors own numbering system, and HiSaturn Navi which has some other system. The Dreamcast uses a new format.
     
  20. Black Squirrel

    Black Squirrel

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    sup

    By the way I added some stuff to this page. It would be lovely if someone more knowledgable could make it... better