don't click here

Games Lagging

Discussion in 'General Sega Discussion' started by Ravenfreak, Nov 10, 2010.

  1. Ravenfreak

    Ravenfreak

    2 Edgy 4 U Tech Member
    3,077
    176
    43
    O'Fallon Mo
    Sonic 1 Game Gear Disassembly
    This is something I've been pondering since I first got this game a few months back. I've first played Earthworm Jim in my Model 1 Genesis, and noticed the game lags and even hangs up sometimes at the beginning of New Junk City. So I played it on the Model 2 Genesis I gave my girlfriend, and not once did it lag or freeze. Any particular reason why? BTW this is the only game I own that does this, all my other games play just fine on my model 1 Genesis.
     
  2. Some versions of the Model 1 megadrive use a different brand of 68000 cpu (Signetics) than others, these systems cannot be overclocked sucessfully, and most likely have other issues too. This is the only reason I can think of to why a game would lag only on a Model 1, unless any of the hardware guru's here have a better explaination.
     
  3. MarkeyJester

    MarkeyJester

    Original, No substitute Resident Jester
    2,192
    405
    63
    Japan
    I ran a google search and it seems that "some" megadrives might contain a different processor "MC68SEC000", possibly the Megadrive 2's, it was apparently a low cost downgraded version of MC68000, but functioned more or less the same for megadrive games (considering megadrive games don't appear to use ALL MC68000 instructions that the MC68SEC000 may not have).

    So yeah, it might be as lukeusher123 said.
     
  4. GerbilSoft

    GerbilSoft

    RickRotate'd. Administrator
    2,971
    76
    28
    USA
    rom-properties
    All Mega Drives have a 68000 rated for 8 MHz operation. Whether a given CPU can be overclocked or not has nothing to do with the CPU's operation at the standard 7.61/7.67 MHz clock rate.

    My best guess would be memory latency. Sega probably used faster memory in later models.
     
  5. doc eggfan

    doc eggfan

    Are you pondering what I'm pondering? Wiki Sysop
    9,681
    232
    43
    ACT
    GreatMegaLD, GreatSC3k, Great SG1k
    Aren't the sprites in EWJ compressed? So the lag would possibly be due to decompressing the sprites?

    Is there a similar issue with Aladdin, or EWJ2?
     
  6. Billy

    Billy

    RIP Oderus Urungus Member
    2,118
    178
    43
    Colorado, USA
    Indie games
    Could this possibly also affect the Sega CD version of EWJ?
     
  7. TmEE

    TmEE

    Master of OPL3-SA2/3 Tech Member
    1,726
    2
    18
    Estonia, Rapla City
    T-04YBSC-A !
    Get rubbing alcohol and give your games and cartslots a good clean. Don't forget pencil eraser, it does wonders with dirty carts. Usually such problems happen with 32X with loose ribbons, but they can happen without 32X aswell, though very rare as game should just outright crash on any problem.
     
  8. DigitalDuck

    DigitalDuck

    Arriving four years late. Member
    5,338
    412
    63
    Lincs, UK
    TurBoa, S1RL
    Alcohol and rubbers. Sounds like a normal night out.
     
  9. TmEE

    TmEE

    Master of OPL3-SA2/3 Tech Member
    1,726
    2
    18
    Estonia, Rapla City
    T-04YBSC-A !
    hahahaha :ssh:
     
  10. Jaseman

    Jaseman

    The programmer has a nap! Hold out! Programmer! Member
    954
    1
    18
    I have both my Model 2 and my Model 1 set up. I must find an EWJ cart and try this out, for great justice!
     
  11. TomoAlien

    TomoAlien

    Member
    48
    0
    0
    Poland
    Quite possibly this. Slight differences between hardware can lead to bad things and well... PS2 has some slowdown problems with some of the PS1 games even though it has the PS1 hardware in it. I've heard that Gradius Gaiden's 7th stage has a slowdown on PS2 that makes it nigh-impossible to play, but there aren't any videos on it, though.

    Hmm... Could you record how the glitch looks? I am interested in such things.
     
  12. TmEE

    TmEE

    Master of OPL3-SA2/3 Tech Member
    1,726
    2
    18
    Estonia, Rapla City
    T-04YBSC-A !
    The Signetics CPU stuff is all lies. You can put a Signetics into a VA6 and it will nicely overclock to 12MHz, even 14MHz but lot of games get glitchy then (and they would with Motorola or Hitachi CPU too).
     
  13. Ravenfreak

    Ravenfreak

    2 Edgy 4 U Tech Member
    3,077
    176
    43
    O'Fallon Mo
    Sonic 1 Game Gear Disassembly
    So I recently bought Jurassic Park and Jurassic Park Rampage Edition, both use the GEMS sound driver, and they lag too. Spinball also lags... so is it possible that GEMS uses more processing power than SMPS?
     
  14. Andlabs

    Andlabs

    「いっきまーす」 Wiki Sysop
    2,175
    1
    0
    Writing my own MD/Genesis sound driver :D
    ...that's really odd, since GEMS mostly runs in the Z80 with very little 68000 interaction — there are a few "mailboxes" that you can set to change what the music does. I wonder how GEMS's 68000 routines could cause lag...
     
  15. TmEE

    TmEE

    Master of OPL3-SA2/3 Tech Member
    1,726
    2
    18
    Estonia, Rapla City
    T-04YBSC-A !
    I'm more willing to believe some resistor is loose or wrong in that MD, causing some open drain bus control signal rise too slowly, thus potentially causing such issues... I really want to see inside that MD...
     
  16. Jaseman

    Jaseman

    The programmer has a nap! Hold out! Programmer! Member
    954
    1
    18
    Has anyone tried a GEMs game on their Model One MD? I, currently, lack a GEMs game, so I can't try.
     
  17. Unsure about Jurassic Park, but isn't it common knowledge that Spinball was coded in C? Every time I've played that game, on emulators or hardware, it has seemed to lag. The one time I got a smooth play, was when running it on a 14mhz overclocked model 1.
    This lead me to believe it was just the C code using more CPU time. Does anyone here know of other C developed games, and there performance on overclocked vs standard hardware?

    The apparent link to GEMS could be because it has a C compatible calling method, meaning that it was widely used in C based games?
     
  18. DigitalDuck

    DigitalDuck

    Arriving four years late. Member
    5,338
    412
    63
    Lincs, UK
    TurBoa, S1RL
    I'm 100% sure the C code is compiled and tested on standard hardware before the games are released.