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Genesis Power FAQ

Modified 18 October 1999

Table of Contents

  1. I want to support Genesis Power...what can I do?
  2. What is the difference between a cartridge and a ROM?
  3. How do you "dump" a cartridge?
  4. What does the alphabet soup mean after your filenames?
  5. I have ROM do I find its checksum or country code?
  6. What is the Sega Genesis?
  7. What is this 32x thingie?
  8. Why bother releasing 32x ROMs if no emulator supports them?
  9. I see ROM xyz is on your list...I'll trade you  a rare copy of Sonic for it...

I want to support Genesis Power...what can I do?

  1. If you have Genesis or 32x cartridges and are willing to send them to us for dumping, contact us. Several of us dump cartridges, so no matter where you are in the world we should have someone nearby that can help us.
  2. If you want to send a cash donation, contact us. All donations are used to purchase more cartridges and dumping hardware.
  3. If you want to make a credit card donation, contact us. Snorter lives near a Funcoland in the Eastern United States, and they will be happy to allow you to purchase a gift certificate in his name over the phone.
  4. You can visit our sponsors. We get a small donation for every click, and that will be used to purchase cartridges.
  5. If you have a web page and want to help, get it sponsored with eAds via this link. We get a tiny donation for every click you get, and it doesn't cost you a thing.
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What is the difference between a cartridge and a ROM?

A cartridge is the physical piece of plastic and circuit board that is plugged into a real Genesis to play games. That circuit board has on it a chip called a ROM (Read Only Memory) that contains the program needed to play a game. The "ROMs" you see on the net are actually dumps of the programs contained in the cartridge's ROM.

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How do you "dump" a cartridge?

There are several ways.

You can have a device that plugs into a real Genesis that lets you dump the cartridge to a file. These devices generally also let you reload the file and play the game without having the cartridge present. The cost of these is generally around US$200-US$300. NeoZeed uses one of these.

Another way is to build a device that the cartridge plugs into and lets you read the contents into a file on a PC. Building one requires some electronics knowledge. Cost of the device is around US$50 in parts plus US$500 of blood, sweat, and grief getting the blasted thing working. Snorter and Cowering use these types of devices. For an example device that is documented on the web, see

The final way is to disassemble the cartridge, remove the ROM chips, and use a general purpose EPROM reader to transfer the program to a file. This is a last resort when nothing else works as it may destroy the cartridge unless you are really careful and know what you are doing.

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What does the alphabet soup mean after the filenames?

These represent the country codes that are embedded in the ROMs. Some companies put checks to only allow certain ROMs to run in machines made in certain parts of the world. Others use the country codes to indicated where the ROM was designed. There can be up to three country codes in each ROM. The codes are:

E = Europe
J = Japan

These codes can also be combined. Many cartridges have the JUE country code, meaning that the cartridge should work on any machine in the world.

In late November 1994, the country codes were changed. The new meanings are:

Hardware Type Main Sales Territories Country Code
0 1 2 3 4 5 6 7 8 9 A B C D E F
Japan, NTSC Japan, 
S. Korea, Taiwan
Japan, PAL                    
Overseas, NTSC N. America, Brazil                
Overseas, PAL Europe, Hong Kong                 

For example, 5 would mean the cartridge was designed for all NTSC machines, A would be for all PAL machines, 4 would be for the same as the old U, and F would be for any machine.

Who cares? Very often, the same game will be different in different parts of the world. For example, E games often have multiple language options, may have different music, and may be more violent than JU games.

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I have ROM do I find its checksum or country code?

Get the program smd. No, we didn't write it. Its only 6k, so don't expect a GUI or anything fancy...if you don't know enough DOS to type "smd" at a command prompt to see what options it supports, DON'T MAIL US ABOUT IT!

The other option is to get cartlist32. READ THE FUNNY MANUAL (RTFM). Then use the program. Its incredibly powerful, and no serious collector should be without it.

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What is the Sega Genesis?

To quote from the excellent Genesis Game Guide by The Scribe:


The year 1987 found Sega in a curious position. The world was awash in 16-bit technology, and personal computers such as the Commodore Amiga and Atari ST were making large inroads on the 8-bit home videogame market. Sega's own 8-bit system, the Sega Master System (SMS), had not fared as well as had been hoped due to the dominance of the Nintendo Entertainment System (NES), but even that revered 8-bit console was losing out to these newer, high-end computers and their impressive array of videogames. Sega had already enjoyed considerable success with 16-bit arcade videogames such as Space Harrier and OutRun, and it got them thinking. The time had come to bring 16-bit technology to the home videogame console market, and Sega
quickly decided to be the first to make the move. If 16-bit personal computers were being accepted so rapidly, they reasoned, then why not 16-bit videogame consoles? Nintendo, their chief competition, already had a 16-bit console in the design pipeline (the Super Famicom, aka the Super Nintendo), but they were in no hurry to market it. They were content to rest on the laurels of 8-bit sales, and thus left themselves wide open to the one-two marketing punch that Sega was about to pull.

Sega's new console was introduced to the Japanese market in November 1988 under the name MegaDrive. It came to the United States in October of the following year as the Genesis, with the name signifying a new beginning in videogame technology (US$350). It made it to Europe and Brazil under the old MegaDrive label just in time for the 1990 Christmas shopping rush. No other home videogame console could compete with Sega´s powerful new 16-bit system at that time, apart from NEC's Turbo Graf/X 16, but that system did not do as well despite an excellent program base. Even so, Sega's system floundered for about two years against the popular NES, until along came a little Japanese game in July 1991 about a feisty blue hedgehog, created by artist Maoto Oshima and developed by programmer Yuji Naka. The rest, as they say, is history. Nintendo had no choice but to rush the Super Nintendo (SNES) to the North American market due to the sudden and massive popularity of Sega's system and the veritable flood of sales that the new game had sparked. That game was Sonic the Hedgehog, and it was the chief reason why Sega knocked Nintendo out of the number one spot in the American and European videogame markets. It was a bitter loss of face for the arrogant Nintendo, and it would be five years before the humilated videogame giant was able to reclaim its throne.

July of 1992 saw the addition of the TradeMark Security System (TMSS) to all Sega 16-bit consoles. This altered the boot-up sequence in two important respects. First, it would not display the message "PRODUCED OR LICENSED BY SEGA ENTERPRISES" unless a specific string of microcode was found in the header of any cartridge plugged into the unit. This was an attempt to stop the proliferation of unlicensed Genesis and MegaDrive games, and was the subject of a famous lawsuit between Sega and second-rate videogame vendor Accolade. Second, it checked the language and video output signals that the inserted cart required and would refuse to boot the cartridge unless they matched those that were hard-wired into the newer consoles. This was an attempt to prevent games made in one market from working in another, but enterprising users quickly discerned how to come up with various hardware hacks that bypassed this feature of the TMSS, and a similar conversion was later incorporated into newer cross-market cartridge adapters.

Due to a lack of third-party support, especially once Nintendo unleashed the SNES to worldwide distribution, the Sega Genesis never became as successful as Nintendo´s 16-bit console. Nevertheless, about 28.5 million consoles were sold worldwide during its lifetime, compared to about 48 million SNES consoles. It took a long time for the SNES to eventually regain the number one spot on the market from the Genesis, and the only reason that it finally overtook it in 1996 was that the Genesis was already declining in popularity. 32-bit videogame systems had been introduced in the last half of 1995 (the Sony PlayStation and the Sega Saturn), and suddenly 16-bit technology didn't look as appealing anymore. Nintendo, having decided to skip the 32-bit wave altogether, helped the underpowered SNES limp on with cartridges fitted with special enhancement chips, but Sega was not content to rest on its laurels. The Sega Genesis was allowed to slowly wither away, and it was officially discontinued in all markets in 1998. In retrospect, it was definitely no mistake to invest in Sega's 16-bit console. Among the 1000 or more titles that were released during its lifespan, which lasted about 10 years (1988 - 1998), are some excellent games that are unique to the system itself and many other evergreens that deserve to be played even today.


There are three flavors of the standard Genesis. The Genesis 1 console is a somewhat rectangular affair with an offset raised circle, originally released in 1988, and is the only model with a headphone jack and volume control. The Genesis 2 console is the now-familiar square low-profile affair first released in 1995, with a streamlined case design and no headphone jack. The Genesis 3 console is a bargain-basement model that was made under license by Majesco in 1998 and somewhat resembles a portable CD player. It is often derisively called "the hockey puck" due to its rather squat appearance and limited capabilities (as compared to earlier models). The Genesis 3 lacks the expansion port of its predecessors; hence you cannot use a Sega CD player with it.

The Sega Genesis was sold under two different names. Genesis is the name used in the North American marketplace. MegaDrive is the original name, first used in Japan and later employed in all markets except North America. Both MegaDrives are essentially identical to the Genesis under the hood, but their case and cartridge styling are a tad different in order to keep them apart.

Sega borrowed the Genesis hardware and later incorporated it into an arcade console called the MegaPlay, which hit the coin-op arcades in 1989. The concept was similar to SNK's multigame cabinets also available at that time. There are two known versions of the unit. The first had Thunder Force 2, Altered Beast, Tetris, Last Battle, Space Harrier 2, and Golden Axe; and the second added Sonic the Hedgehog. According to reports, the unit could be configured however the vendor desired because the internals consisted of a uncased Genesis PCB, a 10-slot multi-cart adapter, and the appropriate coin-op and cart-switching hardware! That meant that all of the Genesis cheats for these titles also worked with their MegaPlay "arcade" versions. The cabinet had two screens, a large gameplay screen, and a smaller instruction screen. Gameplay was timed via additional hardware, and the gameplay screen would flash green to let you know that extra credits were required. The multicart adaptor was later vended as a standalone accessory. (Hey, M.A.M.E. team! Did you know about this?!)

The Nomad (US$150) is a portable Genesis console that was released only in the Japanese and North American markets in 1995. It had a built-in color LCD screen like the one used in the 8-bit Game Gear unit. Along the lines of the Nomad is the MegaJet, of which obscure references can still be found lurking about. This was a Japanese variation of the Nomad that lacked the built-in screen. It was designed for use on Japanese airlines (hence the name), as many planes in the Japan Air Lines (JAL) fleet had small LCD televisions installed into the armrests of each seat for the convienence of their passengers. You could bring your own games, but JAL is reported to have stocked a limited selection of four titles on each flight. Two of the titles known to have been in JAL's rotation included Super Monaco GP 2 and the original Sonic the Hedgehog.

One variation of the Genesis deserves special mention, and that is the Sega TeraDrive. This was an ordinary AMD 386SX-25 PC clone with 1MB of RAM and a 40 MB hard drive, but it also included a built-in MegaDrive as a 16-bit ISA card. The original Japanese TeraDrive was black in color and vended by Sega in conjunction with a now-unknown Japanese company for use by MegaDrive developers. It shipped with a software development kit (SDK) which made it possible to develop your MegaDrive and Mega CD games (the Mega CD accessory appears to have been an option). The Teradrive eventually found its way outside of Japan in late 1993 under the sponsorship of Amstrad, the noted computer system vendor. They changed the case color to cream, beefed up the memory to 2 MB, and made the MegaDRive SDK optional. The unit wasn't very successful regardless of market, and this was largely due to its high price (about US$3000). A souped-up version called the MegaPlus was later offered based on a 486DX-33 CPU machine with 4 MB of RAM, but very few seem to have made it out the door. The TeraDrive and its successor have all but disappeared with the passage of time. Christian Schiller owns one of the rare Euro survivors and won't part with it for any amount of money. He would, however, like to get his hands on a copy of the TeraDrive SDK, as his system did not come with one. Can anybody help him in this regard?

Any game designed for either the Genesis or MegaDrive should work with its foreign counterpart, but the unit may have to be set for the specific market (USA, Japan, Europe) involved. This usually involves a well-documented hardware modification to the unit in question. The Nomad will not work with European releases, but works equally well with U.S. and Japanese games. There are some titles with which the Nomad has problems due to its internal design.


Most folks nowdays don't know that the G/MD included a firmware Sega Master System (SMS) emulator. In fact, it was one of the first videogame consoles specifically designed to support emulation of another system. The SMS emulator is referred to in the G/MD tech docs as "VDP mode 4" and is believed to be triggered somehow by a special signal on the !BYTE line, which is pin B31 of the console's cartridge port. This signal causes the console to download a copy of the SMS boot ROM from a device attached to the unit's cartridge port and then reset, after which it detects the SMS boot code in memory and immediately switches itself into VDP mode 4. The result is a reconfigured console that behaves almost exactly as a real SMS console would under normal conditions.

The PowerBase Converter (PBC), sometimes called the Master Deck, was a Sega-vended accessory available from day one that allowed you to use SMS cards or cartridges with a G/MD console. It either directly supports or can be hacked to work with all G/MD models and third-party consoles except the Nomad, which does not include VDP mode 4 support. It also supports the SMS 3D goggles and light gun for those SMS games that reqire them, and will support dual-language (English and Japanese) SMS games just like it would in normal operating mode. There are two different versions of the PBC, with the second version omitting the SMS card slot.

There was at least one unauthorized third-party SMS adapter released for the G/MD, and that was the no-frills Mega Master by Datel Electronics of the United Kingdom. It also lacked the SMS card slot, and had the SMS PAUSE button mounted on the side of the unit.

There are two documented G/MD carts which are actually SMS carts in disguise and include their own SMS mode trip hardware. These are the ultra-rare Phantasy Star MD by Sega and the equally rare Megadrive 16-in-1 bootleg from Hong Kong. Since they contain their own hardware, no PBC or comparable adapter is required in order to use them with a standard G/MD console.

No Game Gear converter was ever commercially vended for the G/MD, although there was a lot of talk about making one. The name that was passed around was the Mega Game Gear, and it would have included supplemental hardware that would have added to the G/MD's SMS emulation mode the Game Gear specific components that it lacked. Lack of interest seems to have been the chief cause of its demise, although there is currently discussion underway by some reputable Sega hackers to build a homebrew unit.

There is one more emulator that, although never commercially vended, deserves special mention all the same. Sometime around 1991, during the heyday of the Sonic years, Japanese programmer Yuji Naka created an NES emulator for the MegaDrive. It wasn't very good by his own admission and only supported a few games, such as Super Mario Brothers, but it gave him great satisfaction to see Nintendo's games running on Sega hardware. This program has been lost with the passing of years; nevertheless, Yuji Naka's accomplishment is generally regarded as the first "true" videogame emulator (all software, no special hardware required). It is yet another jewel in the crown of Sega's accomplishments with the G/MD hardware.




68000 @8 MHz

VDP (Video Display Processor)

Z80 @4 MHz



Uses CRAM (part of the VDP)
    64 9-bit wide color registers
    64 colors out of 512 possible colors
        3 bits of Red
        3 bits of Green
        3 bits of Blue
        4 palettes of 16 colors
            0th color (of each palette) is always transparent



Z80 controls:

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What is this 32x thingie?

To quote from the excellent Genesis Game Guide by The Scribe:


The year 1993 found Sega busy trying to figure out a way to add polygonal 3D support to the Genesis that would perform at the same level as its arcade games. Nintendo had already led the way in this regard with its Super FX chip for the SNES, and Sega sensed that it was beginning to lose ground against the growing support for Nintendo's 16-bit console. Borrowing from its then-current videogame technology, it developed a prototype product called the SVP Adapter. SVP stands for Super Virtual Play, and the heart of the adapter was a Hitachi SH1 RISC processor - the same found in many of Sega's arcade games. Unfortunately, accurate arcade conversions demanded more horsepower, and so the SVP eventually evolved into a different and more capable unit. The SVP version of Virtua Racing, the only game which had received a full SVP workup, was released as a standalone cart in 1994 in order to give Sega gamers a taste of what was to come.

The 32X was released in 1995 as an add-on accessory for the Genesis. It connected to the Genesis by plugging into the cartridge port and overlaying the base unit's video feed with an additional one of its own. The combined feed was then sent to the user's display via a special cable. It added better color depth, sound, and speedier performance to a standard Genesis console. The main advantage in owning a 32X was that it added the features to the Genesis that it lacked, but were found in its chief competitor, the SNES - like scaling, rotation, etc. - thanks largely to its onboard twin Hitachi SH2 RISC processors. Even though the 32X module took over the Genesis unit (for the most part), it would still allow you to play Genesis games by simply passing the data through from older cartridges and not processing it. 

The 32X adapter was first released in the U.S. in November of 1994 (US$150), with subsequent releases a few months later in the European, Australian, and Japanese markets. A few apparently made their way north and south of the U.S. border to both Canada and Mexico. It was discontinued in the late fall of 1995 due to sluggish sales and the successful debut of the Sega Saturn earlier that summer.










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Why bother releasing 32x ROMs if no emulator supports them?

To quote lamer mail:

"Why the hell do you have 32X roms but no emulators to run it. If you ask me thats super stupid. So you're kinda wasting your time on roms you cant run. Ha. Well thats it."

Someday there will be an emulator, and its author will have been helped by the availability of ROMs. Sure, right now the ROMs just take up disk space. Then again, you can find the ROMs now. Lamers like the above will be begging for them once an emulator is released, and wondering why no-one will help them find the "romz".

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I see ROM xyz is on your list...I'll trade you a rare copy of Sonic for it...?

Just what part of NO don't you understand?

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