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Overclocking Your Sega Genesis/MegaDrive

Posted by simoniker on from the sonic-go-faster dept.

Deven "Epicenter" Gallo writes "I've recently been working on a project to alleviate the slowdown inherent in older game systems. How you ask? By overclocking them! I've managed to perfect overclocking the Sega Genesis / MegaDrive. The processor (a Motorola 68000, running at a stock speed of 7.6 MHz) can be pushed to 16.0 MHz in my experience, and I am still working on higher. The machine doesn't overheat and is entirely stable at these higher speeds."

98 of 372 comments (clear)

  1. I already have a hard enough time... by tsunamifirestorm · · Score: 4, Funny

    keeping up with Sonic ;)

    1. Re:I already have a hard enough time... by ComradeX13 · · Score: 2, Funny

      The question is, can you overclock Dr. Robotnik?

    2. Re:I already have a hard enough time... by playbass · · Score: 2, Funny

      Now its super sonic the hedgehog.

      --
      "The life of a repoman is always intense!" --Harry Dean Stanton
    3. Re:I already have a hard enough time... by LostCluster · · Score: 3, Interesting

      keeping up with Sonic ;)

      That may be justification alone for why the systems were underclocked at the factory. The clock in many games is based not on an actual clock but the speed of the processor... speed things up and you speed everything in the game up, and that's not very playable.

      Unless somebody's found a way to get this thing to run Linux and other non-cartrige programs, this isn't going to be very useful.

    4. Re:I already have a hard enough time... by kisrael · · Score: 2, Interesting

      That may be justification alone for why the systems were underclocked at the factory. The clock in many games is based not on an actual clock but the speed of the processor... speed things up and you speed everything in the game up, and that's not very playable.

      Err, you might be right about programmer's being relatively lazyish (/efficient) and relying on the processor speed for timing...but they could always easily slow down a game that was too fast, but not the opposite.

      Actually...programers don't JUST use the processor speed, or else slowdown would never happen, there wouldn't be a "correct" pacing for a game, just a continuum...few objects -> fast game, some objects -> medium game, many objects -> slow game. Instead, a game has a 'desired' speed, and probably just burns cycles if it's done everything but it's not time to proceed. If there's too much happening, the gmae slows down, and no cycles are burned.

      The underclocking was probably due to the tolerances of the manufacturing process at that point. At this lower clockrate, virtually every chip is usable, at this higher rate, more can't keep up.

      --
      SO YOU'RE GOING TO DIE: The Comic for Dealing with Death
    5. Re:I already have a hard enough time... by Cornelius+the+Great · · Score: 5, Informative

      "That may be justification alone for why the systems were underclocked at the factory. The clock in many games is based not on an actual clock but the speed of the processor... speed things up and you speed everything in the game up, and that's not very playable."

      You're right. Even on newer consoles, like the Xbox, a 1.4 ghz cpu and 128 mb ram upgrade tends to have problems in certain games. Most console games, unlike their PC counterparts, run proportional to the CPU clock for actual game speed.

      In a PC, overclocking the CPU will usually increase frame rate in newer games. Consoles, with their unified architecture, begin to run into compatibility problems when you make certain components run faster, or will usually speed up gameplay proportionally to the clock speed increase.

      Yes, the above applies to the PC-like xbox too, but not to every game. From what I've been told, running Halo co-op splitscreen on that 1.4ghz xbox runs as smooth as silk.

      --
      Sigs are for losers
    6. Re:I already have a hard enough time... by Monkelectric · · Score: 3, Informative
      i'd be surprised if even sega games were so poorly programmed that they depended on the hardware clock speed. Generally what one does is define a unit of time (actual time, clock ticks, cycles, etc -- doesn't matter as long as its uniform), then you define all the motion/game logic as functions of a time delta (time elapsed between the last frame and this current one), since the frame rate is never constant. This way, things happen at a constant rate regardless of frame rate.

      That being said, ive never done any console programming, so who knows :)

      --

      Religion is a gateway psychosis. -- Dave Foley

    7. Re:I already have a hard enough time... by LocalH · · Score: 5, Informative

      The center of your mindset should rest on the vertical blank - that's your 'unit of time', unless you're doing some splitscreen stuff (like the water effect in Sonic), then you utilize the horizontal IRQ (I also call it a line IRQ) to get there. No busywaiting necessary. Frame rate is mostly constant on the classic consoles, in the sense that it's mostly synched with the refresh rate.

      --
      FC Closer
    8. Re:I already have a hard enough time... by Kaboom13 · · Score: 3, Informative

      All units of the same console execute the code at the same rate, so it is common practice to use the hardware speed or frame rate as your time reference. This may not be the ideal, but it's how things are done in the console world (and was common in PC games before computers got so fast it was highly unreliable).

    9. Re:I already have a hard enough time... by Spy+Hunter · · Score: 5, Informative

      His site explains that the games don't, in fact, run faster. Most Genesis games must actually be based on a clock instead of the processor speed. The only effect of the overclocking is that slowdown is eliminated. Don't you remember in Sonic games how if you had more than 20 or so rings and you got hit, the Genesis would slow to a crawl as it drew all the rings bouncing around on the screen? In two-player mode slowdown was even more common. Well if you overclock your Genesis, that can apparently be fixed.

      --
      main(c,r){for(r=32;r;) printf(++c>31?c=!r--,"\n":c<r?" ":~c&r?" `":" #");}
    10. Re:I already have a hard enough time... by AuMatar · · Score: 2, Insightful

      If you're programming to a non-upgradable system (like a console), you frequently DO hard code things to hardware parameters. Thats why a lot of old DOS games are now unplayable- they assumed clock speeds were 33 MHz.

      --
      I still have more fans than freaks. WTF is wrong with you people?
    11. Re:I already have a hard enough time... by Quietust · · Score: 2, Informative
      The clock in many games is based not on an actual clock but the speed of the processor... speed things up and you speed everything in the game up, and that's not very playable.
      The CPU speed is usually NOT used for game timing in cases like this (well, in older NES games it was, but usually not for the faster systems). The main source of timing in video games is the video refresh which, on game consoles, is always 60Hz. Increasing the clock speed simply allows the game to get more work done during each frame so it doesn't have to slow the game down to catch up.
      --
      * Q
      P.S. If you don't get this note, let me know and I'll write you another.
    12. Re:I already have a hard enough time... by The+Vulture · · Score: 2, Informative

      Almost every computer-like machine in existance has a clock in it. This clock isn't necessarily a clock like you'd use for viewing the current date/time, but is in some cases internal to the CPU.

      What units this clock runs in varies from chip to chip, but most of the time, the OS that you're using provides you with a decent way of using it, in some sort of standard measure of time (vxWorks with the BSPs that I've used, for example, provides you with 60ths of a second, which is very convenient).

      This is very important, since especially in cable modems, there are a lot of events that need to be synchronized, and the CPUs change in clock speed (i.e. MHz) on a regular basis.

      In terms of consoles, timing things to the VSYNC is generally popular. In order to properly do double buffering, you need to swap the buffers during the point of time when the raster isn't being shown within the visible screen, or at least in the section you're drawing (otherwise, you'll get tearing).

      That, and it's a fixed timing, either 50Hz (PAL) or 60Hz (NTSC). :)

      -- Joe

    13. Re:I already have a hard enough time... by chiller2 · · Score: 2, Interesting


      Remembering back to my demo coding days (on various Acorn/ARM systems) the reason the game doesn't scream along at some insane rate when the machine is clocked higher is because the update of the framebuffer is synchronised with the v-sync of the display, which on TVs / non multisync monitors was either 50Hz or 60Hz depending on where in the world you bought your equipment.

      If the machine is clocked higher, the only difference is that more code can execute between v-syncs, so the game appears not to slow down when more than a certain number of sprites are being thrown around, etc.

      --
      --- Commission free trading & free stock up to $500 - use http://share.robinhood.com/kelvinp6 :)
    14. Re:I already have a hard enough time... by zeno_2 · · Score: 4, Interesting

      I used to work the help desk at microsoft. (Ok, it was another company, I was never employed by microsoft, thank god.). Anyway, there was this problem when Links 2003 came out, with pretty much any Dell laptop. The problem was, the golfer would swing about 10x fast as normal. After infestigating the problem, we found out that these specific dell laptops would not keep track of windows uptime correctly. We would reboot the laptop, and bring up a program that showed windows uptime, and it would give us completely wrong times. As an example, we would reboot, and the dell laptop would show 48 days uptime. Now, as a "microsoft employee", we didn't have a lot do to, when it came to fixing that particular problem. (it only happened on dell laptops, and we could use windows to verify the uptime was not being recorded correctly. Links 2003 would use that uptime figure to calculate how fast the golfer should swing). In any caes, I was never able to get a straight answer from either Microsoft or Dell as to why the newer dell laptops would not keep the Windows uptime correctly. It was kinda one of those issues that was swept under the rug. So, I can atest to the games out there that use the system clock as a timer to find out how fast to play certain things (probably mainly with animation). This is probably something that is used quite often, especially in a situation (like the xbox)where every system is the same. Oh ya, and I hope the Xbox dies a miserable death.

    15. Re:I already have a hard enough time... by cemaco · · Score: 2, Interesting

      Isn't that why old P.Cs had turbo buttons?

      Whenever I ran into an old DOS game that wast too fast on the newer machine I would just disable Turbo and it would run fine.

      Turbo started disappearing on P.Cs around the time of the mid 486's. That would also coincide with Windows 95.

    16. Re:I already have a hard enough time... by Eil · · Score: 2, Informative


      You can often "overclock" emulators too. Many have a setting somewhere that say something like "instructions per scanline" or "percent of instructrions to execute". Just increase that number and you have an instantly faster (emulated) processor.

    17. Re:I already have a hard enough time... by ByteSlicer · · Score: 2, Informative

      In windows, the uptime is derived from the Tick Count. The tick count is incremented by the kernel, based on a hardware timer source. This source is usually an Intel 8253 Programmable Interval Timer (or compatible device). Some implementations of this timer have been known to be buggy (actually the first one was meant to tick every 20ms instead of the now common 18.2ms). Probably in these Dell laptops, the timer got initialized with the wrong value somehow.

  2. That does it... by SteveTheRed · · Score: 4, Funny

    I'm going to overclock my Timex Sinclair!!!

    --

    I, for one, welcome our new robot overlords
    1. Re:That does it... by fpga_guy · · Score: 2, Interesting

      Or better still, build a Timex/Spectrum in an FPGA and clock it as fast as you like...

    2. Re:That does it... by Kazymyr · · Score: 2, Interesting

      I know the parent is supposed to be funny - but I did have my Sinclair ZX Spectrum overclocked to 6 MHz (from the original 3.5). Some games would run, some not. The clock speed could be changed on-the-fly without any ill effects. Of course at 6 MHz the cassette load/save routines were totally off, so that for loading commercial programs I needed to switch it back to the original speed. But files saved at 6 MHz would load back perfectly fine at 6 MHz. Loading/saving was quicker, too (higher pitch of the carrier + shorter pulses equals more bits per second).

      --
      I hadn't known there were so many idiots in the world until I started using the Internet -Stanislaw Lem
  3. This is about as interesting by Anonymous Coward · · Score: 5, Funny

    ... as the time I slapped a Type-R sticker on my Casio FX-1000 solar-powered calculator. Before I did that, it took 950 milliseconds to calculate 69! Afterward, it calculated 69! in 940 milliseconds flat.

    Or, wait, maybe it was because the sun came out.

    1. Re:This is about as interesting by toddestan · · Score: 4, Interesting

      The factorial function is about the most intensive thing you can do on a little scientific calculator. 69! is ~1.711E98, which is the largest most calculators can go, as 70! factorial has an exponent of over 100. Unless your calculator can handle 3 digit exponents, then you can compute 449!

      Ahh... the memories... back in middle school we used to glitch our solar powered calculators by doing 69! then covering the solar cells, which sometimes resulted in some pretty weird stuff (we could make TI-30's go into some kind of octal mode, also the calculator could sometimes go into some kind of trippy looped animation on the display, or it could change layouts to another TI model, like the TI-30STAT).

      To bring things kind of back on topic, I once overclocked my TI-85. And some of the games did break, though the good ASM programmers didn't rely on the CPU speed, as it would slow down as the batteries wore out, even if you didn't overclock.

  4. And this is good? by djocyko · · Score: 2, Redundant

    I wonder how many games out there assumed they were running on a 7.6MHz machine and now run too fast...

    1. Re:And this is good? by ...+James+... · · Score: 5, Interesting

      You'd think it would be most, but that doesn't appear to be the case:

      I've written my own Nintendo Emulator. Just modified it to execute 5000 CPU instructions per scanline instead of the typical 114. Fired up Super Mario Brothers, Contra, and a few other games and they all appear to work fine.

      I suspect (and I would've thought otherwise before this test) that many games are sychronized with the v blank interval or interrupts. I haven't tested sound, however, since I haven't written that part of the emulator yet.

      --
      get nemulator
    2. Re:And this is good? by LostCluster · · Score: 2, Interesting

      The article seems to imply that Sonic 2 was the only game checked, and that it was fine in normal play but glitched in the 3D half-pipe bonus levels...

    3. Re:And this is good? by Pr0xY · · Score: 3, Informative

      I've also mad a NES emualtor before, and there is a reason the games arent running any faster.

      firstly, many of the games wait for an event (such as the vblank to occur), or sit in an infinite loop waiting for an NMI to process the next frames work.

      Firstly, as you probably know, NES games tend to be very timming critical. Switch to a game that does any cycle counting to determine with things should happen (just about anything made by RaRE should do) and it'll be all fscked up :)

      And as for the speed itself, you aren't executing the instructions any faster, just waiting till more work is done before showing rendering the scanline. This is not the same as the effect of overclocking would have on a real thing. The real with would still execute 113.66667 (or whatever the cycle count it) CPU cycles per scanline...just faster.

      proxy

    4. Re:And this is good? by pidge-nz · · Score: 2, Interesting
      Virtually every video consoles' game timing is tied to the screen refresh i.e. the game carries out the operations required to move sprites, update the background, update the sound being played etc, based the "vertical" refresh rate. There's no point in trying to update any faster, as that's a waste of time, since the changes will not be seen at best, or you get some "tearing" at worst.

      Of course, if you insist on programming in BASIC, instead of assembler like a real programmer (ducks), you deserve to have you game made unplayable :D

      <RAMBLE>

      However, some games which rely on the CPU timing of the console to be a certain number of clock cycles per scan line may get messed up, if that timing is used do things like display a sprite in multiple places on a single scanline. Those of you who have seen/programmed C64 demos with the entire screen in use (no borders) will know about that - that required careful synchronisation with the scanline to fool the Video chip into not turning the border on at the end of the scanline - or simply moving the sprites "down" the scan field so that they are redisplayed. This allowed the 8 sprites the Video chip provided to be used over and over again, so long as the code didn't try to no display more than 8 sprites on a single scan line - extras would go missing - one thing that the game "Commando" violated - it didn't have a very good sprite management system to prevent this occuring. But that never caused it to crash thankfully.

      </RAMBLE>

  5. Hmmm.. by LordK3nn3th · · Score: 5, Interesting

    If you can overclock it so much with a noticeable performance, then why didn't Sega set it like that already, if it's so stable? Certainly it would have given them an edge...

    Pushing a 7.6 --> 16MHz is over 100% more than the original! I have yet to see most people get anywhere near that on normal processors.

    --

    ---
    Never criticize religion on Slashdot. You will be modded down for "Troll" no matter how factual it is.
    1. Re:Hmmm.. by jaxdahl · · Score: 2, Insightful

      Reliability.

      You don't want to have to replace thousands of pricey (back then) consoles if chips prematurely fail.

    2. Re:Hmmm.. by BW_Nuprin · · Score: 5, Interesting

      Its possible that later production Gennys had better processors that were clocked down to maintain the same speed as the older models. In the five or so years that Genny was around, I'd expect that there were many many improvements to the 68000. I'd wager that the last couple Gennys off the line could be overclocked three or four times over without a sweat.

    3. Re:Hmmm.. by Arker · · Score: 4, Insightful

      That's the point. The article apparently claims that it remained stable at over an additional 100%. Now, not all processors are alike, but if one of those can handle up to that, shouldn't others be able to handle a fairly good amount of overclocking as well?

      Well you've got to remember that these things were made for several years. Just a guess, but I'm thinking by the time the last ones they sold were made, Motorola probably had long since quit making 7.6mghz chips, and were just shipping whatever their bottom of the line was at the moment and underclocking it.

      Also, you have to remember even if that's not the case, there's a lot of variability in chips. Just because this guy got his to run at this speed reliably, doesn't mean they all would.

      --
      =-=-=-=-=-=-=-=-=-=-=-=-=-=-
      Friends don't let friends enable ecmascript.
    4. Re:Hmmm.. by LordK3nn3th · · Score: 2, Interesting

      Yes, it's very possible they were underclocked for compatibility reasons. But I doubt they would've gotten a freak chip that could handle so much... I'm sure if that one could get so high, others could get high too (maybe not as high, but still high).

      --

      ---
      Never criticize religion on Slashdot. You will be modded down for "Troll" no matter how factual it is.
    5. Re:Hmmm.. by IntergalacticWalrus · · Score: 2, Insightful

      "The article apparently claims that it remained stable at over an additional 100%"

      Yes, but for how long? Sega wanted their machines to run a few years tops. Overclocking your Genesis CPU and still having it running after a week barely proves that Sega has underpowered it.

    6. Re:Hmmm.. by ArsonSmith · · Score: 2, Funny

      The analogy in nature? Ants can carry 50 times their weight, but we can't.

      I could easily care 50x an ants weight. you weakling.

      --
      Paying taxes to buy civilization is like paying a hooker to buy love.
  6. Now what about other consoles? by SDMX · · Score: 3, Funny

    Someone needs to recreate this with a NeoGeo. Metal Slug needs to be played free of all that ridiculous slowdown. =]

    1. Re:Now what about other consoles? by Talez · · Score: 3, Informative

      NeoRageX lets you overclock the 68K in the .ini file. Set it to 24MHz and no more Metal Slug slowdown! :D

  7. Check results first? by BW_Nuprin · · Score: 5, Insightful

    I don't recall exactly, but I think you could 'overclock' the genesis in older emulators like Genecyst, so perhaps that would be a good way to check to see how well games run overclocked before you actually futz with your real Genny. I would think that many games would have timing problems at a speed greater than stock, particularly those that use raster effects. I can't say for certain, but I know my old Gameboy Color raster effects would break completely if I overclocked them. I would wager that racing games would probably suffer the worst.

    1. Re:Check results first? by LocalH · · Score: 2, Insightful

      Depends on if you have a hardware line IRQ or not. Hardware IRQs are always friendly to overclocking, while busywaiting never is.

      --
      FC Closer
  8. Correct me if I'm wrong... by kundor · · Score: 3, Insightful
    But since games that can't run well on a console platform simply aren't published for that platform, isn't this somewhat useless?

    Granted, it's nice for the coolness factor, but unlike PCs, newer and flashier games only come out for beefier platforms and can't be run on the old ones anyway, no matter how fast they're going.

    1. Re:Correct me if I'm wrong... by YOU+LIKEWISE+FAIL+IT · · Score: 4, Interesting
      But since games that can't run well on a console platform simply aren't published for that platform, isn't this somewhat useless?

      There isn't enough correction in the world. A lot of games get released for consoles with noticable periodic slowdown - the classic example is the Metal Slug series. Still happening today too, I notice the occasional wad of dropped frames playing my XBox or Gamecube.

      --
      One god, one market, one truth, one consumer.
    2. Re:Correct me if I'm wrong... by qoa · · Score: 2, Funny

      I liked to think of the slowdown on Metal Slug for Saturn as adding to the excitement. Kind of like an action movie.

      --
      Every normal man must be tempted at times to spit upon his hands, hoist the black flag, and begin slitting throats.
  9. Boy do I remember the slowdowns by General+Sherman · · Score: 3, Interesting

    Whenever I would play Road Rash 2 in split screen mode, the Genesis was noticeably slower. I was always disappointed with this, shame I don't have it anymore.

    --
    - Sherman
  10. sega genesis by Coneasfast · · Score: 5, Informative

    for those of you who don't know, 'genesis' is the north american term whilst 'mega drive' is the UK (and european?) term

    here are the specs and some history

    --
    Marge, get me your address book, 4 beers, and my conversation hat.
    1. Re:sega genesis by IntergalacticWalrus · · Score: 5, Informative

      In fact "Mega Drive" is the original japanese name too. That stupid "Genesis" name was in north america only.

  11. Re:hrm by Anonymous Coward · · Score: 2, Informative

    well, if you're trying to run an old DOS game you can do that with DOSBox, which comes in handy a lot of the time.

  12. Videos.. 26 meg? by E1ven · · Score: 4, Informative

    The site, including the videos, are convieniently mirrored to sq7.org

    --
    Colin Davis
  13. 16mhz is fast! by Snagle · · Score: 5, Funny

    16mhz is what the Palm Zire runs at too. That means if someone ports Palm OS 4.1 and you attach a VGA/LCD thingy you can have a Sega brand PDA. True, you are sacrificing portability, but hey, I think there are some kids at my school with pockets big enough for a Genesis.

  14. FPS? by red_dragon · · Score: 3, Funny

    So now kids will start bragging about how many frames per second they get on Flashback, eh? That's just what we needed right there.

    --
    In Soviet Russia, Jesus asks: "What Would You Do?"
    1. Re:FPS? by richie2000 · · Score: 3, Funny

      What, you haven't overclocked your TV?

      --
      Money for nothing, pix for free
  15. anyone want to place a bet.... by npistentis · · Score: 3, Funny

    as to how high his cute little hit counter registers before his server reaches critical mass? maybe he should've turbocharged that machine first...

    --
    Gentlemen, you can't fight in here! This is the War Room!
  16. They knew it all along by Space+Coyote · · Score: 2, Funny

    It's obvious that this could be done, after all the Genesis has Blast Processing

    --
    ___
    Cogito cogito, ergo cogito sum.
  17. Poor Server by General+Sherman · · Score: 4, Funny

    It's a shame he didn't overclock his server to twice it's original speed. Those 10-25MB .avi's really don't help.

    --
    - Sherman
  18. Most of them... by LucidityZero · · Score: 2, Informative

    Most (if not all) of them, I'd assume.

    When you're developing a game for a specific platform that will never change, why would developers use any sort of time-based algorithm to determine game speed? You'd end up with a smoother/prettier game if you merely used the limits of the hardware to control the speed of your game.

    Especially back in those days where most of the games really DID push the limits of the hardware. Almost any game would slow down with too many sprites on the screen, etc.

    I'd assume almost any Genesis game would play very, very quickly on an overclocked system.

    --
    Sig.i>
    1. Re:Most of them... by LocalH · · Score: 3, Informative

      If the game just updates the screen whenever the hell it feels like it, busywaiting until it's time, then yeah, it'll fuck up. But any properly coded game will utilize the VINT to synch to the refresh rate. Sonic 2 does this for sure, you can even see the garbage in the bottom border where the game is initializing the VDP for the next frame.

      --
      FC Closer
  19. An easier way... by wardomon · · Score: 4, Funny

    Plug it into the 220 outlet behind the stove. It'll run really fast for a couple of seconds and then you can get on with your life.

    --

    - - - If the sun is a star, why can't I see it at night?
  20. How does it work with other genesis attachments? by Recovery1 · · Score: 4, Interesting

    Now here's an interesting thought. What would happen if you hooked one of these overclocked Genesis into the Sega CD or 32X attachments? As I recall the whole process of getting the Genesis and Sega CD to work together in parallel was a challenge to begin with because of different clock speeds between the two CPUs in each device.

    My guess is he hasn't tried it or it doesn't work, as he doesn't elaborate on it.

  21. - Overclocking DOES NOT cause games to speed up! - by Epicenter713 · · Score: 3, Informative

    Just no slowdown! :)

  22. Sega slowdown... by Anubis333 · · Score: 5, Informative

    Slowdown is an integral part of older consoles. Modern day emulators that can easily push these consoles with no slowdown at 60FPS impliment a technique to fake "slowdown." It's a lot easier to just grab a genesis emulator for your Dreamcast or Xbox than attempt a hardware mod like this.

    1. Re:Sega slowdown... by LocalH · · Score: 3, Funny

      WTF? You're trying to say that the NES' horrible OAM cycling is INTENTIONAL and is a valued part of the experience? You're on crack.

      --
      FC Closer
  23. 3D Graphics on a TI-85 by KalvinB · · Score: 2, Interesting

    While in High School I was always coding various things in BASIC on it and one day when I demonstrating how to map 3D objects by placing the sonic sensor on an overhead cart and rolling it under light fixtures, this kid in my calc class goes "you expect that thing to act like a Pentium." I used TI-BASIC to learn how to do 2D translation and rotation and touched on some 3D. I made the first and possibly only graphical adventure game for it complete with text entry and a cursor to click on objects.

    A few years ago I gave it to a friend who needed a TI but I'm pretty sure the Intel Inside Pentium MMX sticker is still on the back of it.

    Ben

    --
    Work Safe Porn
  24. Re:How does it work with other genesis attachments by Epicenter713 · · Score: 2, Informative

    It works great .. only thing is, DO NOT boot the Sega/Mega CD over 12 MHz or it will get panicky. The best method is to boot at 7.6, run the game. Then once at the title screen halt and go to the higher speed. The 32x works great in my experience as it doesn't rely on the 68000 much .. it uses a pair of its own SH-2 chips.

  25. Great, it's in English... by SavannahLion · · Score: 3, Informative
    I've had a cached URL to overclocking your Genesis/Mega Drive for a long time. Unfortunately, it's in Japanese and Babel Fish makes it really tough to understand technical instructions.

    I wonder if the author of the article at Epic Gaming read the Japanese article and got the idea from there?

  26. WRONG, WRONG, WRONG, WRONG, ALL WRONG by LocalH · · Score: 2, Interesting

    NTSC does 60Hz, PAL does 50Hz. Most games update the screen every frame, a few will do it on two's. This actually has a use with all games that are programmed correctly, especially those which rely on raw CPU time.

    It'd also be nice to play around with in a C64-styled demo, banging on the VDP with the increased cycles available at the higher clock speed. I wonder what happens when you try to hit the VDP too fast. To compare, with a SCPU-equipped C64, the 65816 simply blocks until the 1MHz bus frees up, if it needs to.

    --
    FC Closer
    1. Re:WRONG, WRONG, WRONG, WRONG, ALL WRONG by Phybersyk0 · · Score: 2, Interesting
      Um. You must have owned an AMIGA also. What you're referring to was quite an issue on the AMIGA, either timing your graphics/music to it's CIA (complex interface adapter) chips or VBI (vertical blanking interval) timing in the FAT AGNUS animation co-processor.

      There were always hacks for the Amiga that allowed you to alter the timing for things like graphics, or in most common cases, the playing of music modules (MODS).

      The Motorola MC68000 was a comparitivly fast cpu amongst it's peers (IIRC the MAC LCII & the Atari ST had this too), HOWEVER, the CPU was much slower that what was needed in the Amiga, and why job-specific custom chips were created.. but I digress...

      Later revisions of the Amiga 500 included a Motorola MC68010 cpu which was electrically compatible with the MC68k, and was a reasonable replacement.. It ran at something like 11Mhz...

      So... You should be able to do that to the Megadrive/Genesis also, without any real problems. I remember specifically playing Altered Beast, and each time you'd take on the 2nd level boss (the wierd octo-eye-puss thing) and it would get slow.. man that sucked.

  27. Famous last words... by djupedal · · Score: 4, Funny

    The machine doesn't overheat and is entirely stable at these higher speeds.

    The machine doesn't overheat and is entirely stable...

    The machine doesn't overheat ...

    The machine doesn't ... ...work ?

    1. Re:Famous last words... by djupedal · · Score: 2, Funny

      ...this is how most people delude themselves in the name of 'science'.

      The goal was to overclock...if they fall off the bench and break in the process, they failed due to overclocking.

      Reminds me of how in Japan, if you are injured in a car accident, and don't die within the first 12 hours, you are not counted as a traffic fatality.

      Parachutist dies from the sudden impact with the ground, not because he jumped out of an airplane?

      Man eats glass and dies....not because he ate glass, but because he swallowed? - c'mon....

  28. street fighter 2 SNES by sewagemaster · · Score: 2, Interesting

    i remembered having massive slowdowns in streetfighter - especially if you're using guile and execute any combo more than 4 hits

    my favorite combo... but lags in SNES...
    jumping fierce + close fierce uppercut + sonic boom + referse fierce + sonic boom.

    ironically this was under SF2 TURBO

    --
    my blog
  29. We can't let the Sega fanboys beat us. by Maul · · Score: 3, Funny

    Finally, we can recreate the glorious console wars of the 16-bit era!

    I'm going to overclock my Super NES.

    I'm not going to let those Sega fanboys get the upper hand on this. They already taunted us SNES owners about their "blast processing" in the early 90s.

    --

    "You spoony bard!" -Tellah

    1. Re:We can't let the Sega fanboys beat us. by Epicenter713 · · Score: 2, Informative

      Heh, sorry to burst your bubble, but even at higher clockrates the SNES can't outperform the MegaDrive/Genesis. Too inefficient. Let's call it the 16-bit intel/amd war. ;) But I am working on SNES overclocking. It'll take time, but it's the same basic procedure as with the NES ..

    2. Re:We can't let the Sega fanboys beat us. by JayBlalock · · Score: 2, Insightful
      Oh gods, I'm having bad flashbacks.

      Ok, short version:

      SNES - slow as hell processor, makes up for it with specialized GFX and Sound chips.

      Genny - Faster processor, better memory usage, but fewer colors onscreen and no built-in scaling and rotation.

      But really, if you aren't running NeoGeo, you're eating squirrel burgers. ;-)

      --
      Bush: He's Liberal in all the wrong ways.
    3. Re:We can't let the Sega fanboys beat us. by evilviper · · Score: 2, Funny
      But really, if you aren't running NeoGeo, you're eating squirrel burgers. ;-)

      Considering the price of the system, I'd say:

      If you aren't running NeoGeo, you can afford to eat!
      --
      Slashdot gets worse every day... Pipedot: News for nerds, without the corporate slant
  30. Any way to get homebrews on real hardware? by Kris_J · · Score: 4, Interesting
    Overclocking an; Atari 2600, Atari 7800, Gameboy, GBA, C64 (or any system with a disk drive option) or even a PSX/PS2 is really cool because you can get homebrew code onto real hardware with some sort of RAM or flash cart, or writable media. Enthusiasts can subsequently write new programs that use the extra clock cycles. However, I don't know of any way to get ROMs onto a Genesis/Mega Drive -- is there one?

    Meanwhile, anyone in the Perth area that wants a Mega Drive to try this on, you can have one of mine if you'll convert a second for me.

    1. Re:Any way to get homebrews on real hardware? by LocalH · · Score: 2, Informative

      www.tototek.com They sell a flash cart in 32Mbit and 64Mbit varieties. The 64Mbit one also supports 32x games.

      --
      FC Closer
    2. Re:Any way to get homebrews on real hardware? by Eil · · Score: 2, Interesting


      However, I don't know of any way to get ROMs onto a Genesis/Mega Drive -- is there one?

      Cart copiers exist, but they tend to be either incredibly expensive, incredibly hard to get, or both because the companies that made them stopped selling them once new systems came out. The biggest market for copiers were asian countries with lax copyright laws and rampant piracy. Reportedly, a year or two after the PSX came out, it wasn't uncommon to see someone throwing their perfectly-working copier and stack of floppies (games) right into the dumpster. Now a decent SNES copier can go for upwards of $250 on ebay.

  31. What about the Z80?? by Anonymous Coward · · Score: 3, Interesting

    The Sega Genesis is a dual processor system containing both a 68K and Z80. Some games are sensative to the timing between the two processors. If you overclock one and not the other some assumptions about the timing is going to break. In the cases of his tests it appears to produce problems with the music since that is what the Z80 gets used for in Sonic. But in other games the Z80 is also used for video effects such as flashing icons. Even if you can get the 68K another 50% faster, you still haven't gotten the entire system correctly clocked at the new rate unless the Z80 can also handle being clocked another 50% faster.

    1. Re:What about the Z80?? by Epicenter713 · · Score: 2, Informative

      The Z80 is barely used by games save for music .. so it generally doesn't need to be raised. Also, cranking up its clock will likely make sound pitch shoot up..

  32. Re:lol by PACHUKA · · Score: 2, Informative

    http://www.vuni.ne.jp/~tamari/megadrive/md.html here's where the original information was stolen from. It's a fairly common item, that's been passed on in SEGA development communities since 1999, when this article first surfaced. So Epicenter's "work" basicly means "copy and paste".

  33. You know... by TWX · · Score: 4, Funny

    " ... as the time I slapped a Type-R sticker on my Casio FX-1000 solar-powered calculator. Before I did that, it took 950 milliseconds to calculate 69! Afterward, it calculated 69! in 940 milliseconds flat."

    Personally, I prefer my sixty-nine bangs to take a little longer than that...

    --
    Do not look into laser with remaining eye.
  34. Re:- Overclocking DOES NOT cause games to speed up by LoadWB · · Score: 5, Insightful

    I am glad to see this as a root post. Anyone who has ever dug into the internals of the Amiga, Mac, or Atari ST hardware has found that moving to faster 680x0 CPUs did not affect game speed, only the amount of lag (we called it "bog") in a game.

    I have nearly two decades of experience with the 680x0 CPUs in the Amiga systems. I remember being absolutely thrilled when Sega used the 68000 CPU in the Genesis. I hacked an original unit which had the 68-pin package with a 68010. Honestly, I do not remember the full results, but I recall I was still able to play the majority of my collection (two carts at the time, hahahaha.)

    I also toyed with the idea to replace the 68000 with an MTec 68020 accelerator pulled from my Amiga 500. I never tried it, and I still am not so sure it would have worked anyway. If the AmigaOS was a little less hard-wired to the Amiga hardware architecture, given a little work, we might could have seen AmigaOS running on a Genny ;) Hell, we might still be able to see that just for kicks.

    Having gone from 68000 to 68040 in all its discernable steps (I still dream of a 68060/PPC accelerator for my A4000,) I have been able to bring all of my games with me. The only problem I have is with expected timing of the OCS chipset versus the AGA chipset. But there are a number of great hard drive installers which over come this, as well as system "degraders" which place the computer in a state almost identical to the original Amiga hardware.

    In any case, I'm inspired by this article and look forward to dropping a 12MHz clock generator in my Sega II (provided its CPU will support it.)

    (climbing up on soap box) It is also worth mentioning that us old-hat gamers take a lot of shit for being so nostalgic and blah blah blah, aching for an era long-past. I got news for those who cast stones, many of those games were FUN, and down-right phuqn great. I will not say that none of my collections are nostalgic -- I have a number of Atari 2600 carts which I never played then and do not play now other than for testing, simply because they are Atari. But the majority of the games I collect (Amiga, Atari, Sega, NES, TI, C64, and others) WERE fun, and are STILL FUN.

    How many people are still playing a "dead" console because the games rocked and you cannot get them for "modern" consoles? PS1 is almost 10 years old, and yet it still has a large following. I bet in 10 years there will still be a large faction of people playing the original XBox because some of the titles will not be available on newer consoles, or just will not play the same. (I do wonder how game play of XBox 1 games will be on the XBox 2...)

    Well, enough of that.

    END OF LINE

  35. Alternate suggestion. by gklinger · · Score: 2, Informative

    Rather than overclocking the 68000, he should consider upgrading the CPU. The Motorola 68010 is both pin and insstruction compatible and it has a slightly higher range of operational clock speeds. Way back in the day (I've always wanted to say that!) I upgrade dozens of Amiga 1000s without a problem. And yes, the upgrade was, for all intents and purposes, useless. I would tell people that and they would still want the upgrade so I let commerce take its natural course.

  36. Re:How does it work with other genesis attachments by forgotmypassword · · Score: 2, Informative

    Seeing that the 32X removed all of the slowdown from all of my games anyhow, I really don't see the point of any of this.

    --
    A Usenet Troll Triumphs on Slashdot
  37. I always like that feature :) by Anonymous Coward · · Score: 2, Funny

    I always like that feature :)
    Gives you time to go "ARGH!", punch something, and recover :::)))

  38. Many games use the Vertical refresh interrupts by Anonymous Coward · · Score: 2, Informative

    Many, if not most, games drive their logic using the vertical refresh interrupt. This tells them that the scanline is not in a visible part of the screen, so that now is a good time to do redrawing and so forth.

    The logic parts of the game (AI and so forth) are usually done asynchronously, then the redraw is done on that edge so as to avoid tearing.

    It's much the same as modern day graphics cards frequency lock settings, except that in older games everything tends to be dependant on the graphics refresh.

  39. Kind'a hard to see the difference by Aqua+OS+X · · Score: 2, Interesting

    it's kind'a hard to tell the difference when we're looking at an AVI file with a set frame rate.

    --
    "Things are more moderner than before- bigger, and yet smaller- it's computers-- San Dimas High School football RULES!"
  40. Re:lol by gklinger · · Score: 3, Insightful
    Against my better judgement, I'm going to give you a couple of suggestions...

    First off, this place is for discussion and it is generally a good idea to counter opinions with your own rather than trying to censure people. Let moderators decide what is and isn't appropriate. That's what the system is for.

    Secondly, it appears as if you've created multiple accounts so you can make posts supporting yourself without it appearing as if you're doing (even though it's patently obvious). If this is not the case, I find it to be a remarkable coincidence that three new users with almost consecutive IDs, you (761169), laggerzero (761187) and Light Serif (761190) all commented in the same thread right after one another. Further, those comments were the only ones those users ever made. Quite a coincidence indeed.

    Last but not least, and please take this as a constructive suggestion and not an insult: Take a deep breath and try to relax. You're working yourself into a lather unnecessarily and in the process, making yourself look a tad silly. Remember, this isn't a popularity contest. It's just Slashdot.

  41. No... by hyc · · Score: 4, Informative

    You're off by at least a decade. Maybe the original Pong and Atari 2600 were cycle-counters. Everything made after that used VBI timing. Newer arcade boxes like the NeoGeo used 68020s, which of course had instruction caches that made cycle-counting impossible.

    I'd love to get an Atari ST emulator up and running Spectrum Holobyte's Falcon, overclocked. It would be cool to see it running at a smooth frame rate.

    As I recall, by the end of life the Motorola 68000s were all made as 16MHz parts. The slower parts were simply not made or sold any more. Also, even when they were genuine 8MHz parts, they were pretty reliable with 50% overclocking; we did this sort of thing all the time in Atari STs before the 68020 and 68030 upgrades got popular.

    There were limits to what you could gain though, since the 68000 had no on-chip caches of any kind and the system bus generally couldn't handle as much of a speedup. The better upgrades included a memory cache with the accelerated 68000 on a daughterboard that plugged into the original CPU socket, to allow the processor to run at full speed without disturbing the rest of the system. It was all a dicey job though; the tolerances in the rest of the system were pretty ragged. I remember having to desolder a bunch of 74LS series buffers and replace with 74HC or AS series or somesuch that worked at faster clock rates, more noise immunity, etc., adding tantalum capacitors everywhere, etc... Ah, the good old days.

    --
    -- *My* journal is more interesting than *yours*...
  42. Uh... The answer lies with Nintendo... by Chordonblue · · Score: 3, Informative

    At least with the SNES. Take Gradius 4 for example - one of the first releases for the SNES. The slowdown in that damn game was unbelievable at times and yet you look at something like Pilotwings or Mario and you'd never see it.

    Why?

    Well, as it turns out, Nintendo underpowered the SNES' processor BIG TIME. In the first releases only Nintendo was permitted to use cartridge-based 'assist' chips that assisted with animation of larger objects. This explains why Nintendo's games always looked so golden on SNES.

    Later Nintendo licensed the chips for 3rd parties but really screwed them for it. This was back in the day when Nintendo made all the games themselves, chose which ones would see the light of day (yes, even 3rd party ones!), and charged an arm an a leg for those assist chips.

    --
    "...Well, there's egg and bacon; egg sausage and bacon; egg and spam; egg bacon and spam; egg bacon sausage and spam..."
  43. Nintendo did this... by Chordonblue · · Score: 4, Informative

    A lot of SNES stuff had 'assist' chips in the cartridges. Most were basic 'blitter' chips, but there were some that actually had co-processing on board for 3D graphics (SuperFX). Games like Starfox and Stunt Race FX simply would not have been possible on that console otherwise.

    I wonder if you're thinking of a special version of Ecco that ran on the 32X Genesis co-processor.

    --
    "...Well, there's egg and bacon; egg sausage and bacon; egg and spam; egg bacon and spam; egg bacon sausage and spam..."
  44. Fixed speed difficult without external timebase by noidentity · · Score: 3, Interesting

    A game with a varying number of on-screen objects which achieves consistent speed without relying on an external timebase is somewhat difficult to code because the execution time of every routine must be taken into account to determine the proper delay until the next frame. It's unlikely that the overall frame rate of a game would be normally determined by CPU cycles used (it will be when there is too much to process in the usual frame interval). In addition, video hardware on some consoles only allows access between frames (during vertical blanking). Even where it doesn't, if the game's frame rate isn't synchronized with the video frame rate, when updates are made in the middle of the video frame, the next completed video frame will have a split across the middle with the old frame on top and the new frame on the bottom.

    Depending on the CPU speed for short self-contained routines which access hardware in a time-critical way is probably more common, and not bad practice, since the older consoles were kept compatible at the hardware level. Keeping hardware the same across board revisions allowed elimination of a cycle-consuming software abstraction layer.

    1. Re:Fixed speed difficult without external timebase by TrancePhreak · · Score: 2, Informative

      Most consoles at that time operated in a fairly similar fashion. The video hardware would draw the frame, and then a v-blank would be triggered. During the v-blank, you could execute code and manipulate the video data. When not in v-blank, you could calculate game related things. For example, a common game would manipulate a local set of data with the information for the sprites. The v-blank is triggered and the local data is copied into vram. V-blank ends and the process begins again.

      --

      -]Phreak Out[-
  45. Overheating by Jacek+Poplawski · · Score: 2, Funny

    Overclocking 8-bit computers like Atari 800XL is very good thing, because these computers where often used to keep your legs warm in winter (if you don't believe me, ask older collegue, who had 8-bit computer), so additional overheating can only help :-)
    Stability is of course different problem. Overclocked Atari may work almost as badly as Windows XP.

  46. Re:Wow by hyc · · Score: 2, Interesting

    Thanks for the thought.

    I think it's ironic, in an industry where the common practice was to build chips targeted at a particular speed, and sell the ones that didn't pass certification as slower parts, that Motorola was stuck selling perfectly good 16MHz chips as 8MHz chips just to keep that price point open. (There was absolutely no difference between an 8MHz and 16MHz chip by the end of their product life.) And there were people routinely running their 16MHz chips at 32MHz, because the fact was that they were produced off the same process used to make the 25MHz 68020s, and that core was the same as the 32MHz 68030. It was all the same silicon, all of it good enough for 32MHz.

    --
    -- *My* journal is more interesting than *yours*...
  47. It can overclock Sonic, but.... by ProppaT · · Score: 2, Funny

    The real question is, can it overclock my Ballz?

    --
    Wise men say, "Forgiveness is divine, but never pay full price for late pizza."
  48. that 'slow-down' was a feature by CAIMLAS · · Score: 2, Interesting

    I don't know about anyone else, but I actually appreciated it when my NES or genesis would slow down. It usually happened in a particularly difficult spot, and it allowed for quicker response on my part. Such slowdown is the only reason I ever managed to beat Super Mario Brothers.

    Since I couldn't afford a game genie, it was a nice substitute at times. :)

    --
    ~/ssh slashdot.org ssh: connect to host slashdot.org port 22: too many beers
  49. But I won't be able to read fast enough... by generationxyu · · Score: 2, Funny

    How would I ever memorize the Zero Wing Intro?

    --
    I mod down pyramid schemes in sigs.
  50. 68k - 68010? by Nimey · · Score: 2, Insightful

    Is it possible to desolder the 68000 and replace it with a 68010? The '10 had better integer performance and had an identical pinout.

    --
    Hail Eris, full of mischief...

    E pluribus sanguinem
  51. Or... by Bert64 · · Score: 2, Interesting

    Why not pull the 68000 out and replace it with a 68010 chip, which is pin compatible, faster at the same clockrate and able to run at higher clock rates anyway...
    I always thought the megadrive 68000 cpu was clocked at 12mhz anyway, it was the Amiga 500/600 series machines which used 7mhz 68000, and one cheap upgrade path was to pull the 12mhz cpu out of a megadrive

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