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Development: SMSReader - Frequently Asked Questions


Your queries answered (or not)...

Ask away! If you have a question about the SMSReader or 8-bit Sega cartridges in general that you'd like to see answered here, e-mail me and I'll add it next time I update the page.

Why did you create the SMSReader?

Firstly, because I wanted the ability to dump the cartridges I had, and secondly, because there were no other parallel port cartridge reader designs on the Internet. (Andrew Lindsay's reader, the first - and only? - design to be published, requires a proprietary ISA card.) I also wanted the ability to write to SRAM based cartridges, because I was getting sick of burning an EPROM each time I wanted to play a ROM or test a piece of code.

Why won't the DOS software work under Windows NT/2000/XP?

Because NT doesn't allow direct port writes, which the software requires.

You should be able to use Maxim's GUI software under NT/2000/XP with the NT drivers supplied. I haven't been able to test this myself, however.

I read this cartridge - why is the ROM different to the version I downloaded? (The checksum is fine.)

Make sure the ROM is the correct size, and not an overdump (i.e containing more data than was in the original ROM). If the stored header checksum is the same as the one for the version you downloaded (Maxim's Header Reader will show this information), then it is the same version and your dump is bad. ( Alternatively, it could be that you have made a good dump, and the version you downloaded was a bad dump.) If the stored header checksum is different than the version you downloaded, then it could be an alternate version. Look in the MEKA.NAM file and you'll see a lot of games listed more than once - these are multiple variants of the same game. I expect there are a lot of variations out there just waiting to be discovered. But please ask someone at SMS Power if you're unsure, there are a lot of bad dumps floating around and it would be a shame to add to them. Read the Guide to Responsible Dumping for more information.

How can I tell for certain if this game is undumped?

Try loading it up in Meka... if it's not in the MEKA.NAM file, it is possible that it hasn't been dumped before. It could very well be a bad dump, of course - make sure you have the checksum option enabled when reading Master System cartridges, and the verify option enabled when reading any cartridge. You should always redump the cartridge a few (three or four) times, removing and re-inserting the cartridge each time, then compare the files. And do perform the modification mentioned in the SMSReader-Troubleshooting section, as it will significantly reduce the likelihood of bad dumps.

If it is indeed an undumped game, and you're certain the dump is good, then please contact someone at SMS Power with the details :-)

OK, so I've built the SMSReader, and started dumping my SMS cartridges. What about Game Gear, SG1000, SC3000...?

Only SMS cartridges from non-Japanese territories can be read with the SMSReader as-is. Other cartridges and cards use different connectors, and will have to be read with the aid of an adaptor. I'll cover the building of such adaptors in a future update.

Why can't I read Codemasters games?

Unlike most third parties, Codemasters manufactured their own cartridges. They use a proprietary mapper which requires a connection to the Z80 clock line. This mapper is not supported by the current SMSReader hardware and software - that's not a huge loss, though, as it's possible to dump the games either by desoldering the ROMs and reading them directly, or by using the SMS to read the cartridge and transfer the data to a rewritable cartridge, which in turn is read on the SMSReader.

Hey, what about the built-in games? Can I dump those?

You can dump the BIOSes, and use them in an emulator which supports BIOS images (e.g. FreezeSMS and AGES). The BIOS ROMs themselves are physically the same as mapped cartridge ROMs (to identify the ROM, look for a five digit number prefixed with MPR-), so you can desolder them, insert them into a single-chip cartridge board and read them as you would a cartridge of the same size. Alternatively, it's possible to use the SMS itself to read the BIOS with the aid of a program stored on a rewritable cartridge. The program relocates into user RAM and transfers the BIOS data to the rewritable cartridge, so you end up with a cartridge containing the BIOS which can then be dumped on the SMSReader in the normal way

What's the story with Japanese SMS games? Why do they need to be patched for use on a US or Euro SMS?

The BIOS used in the US and European SMS has a routine which calculates the checksum of the ROM, and compares it to the stored value. Additionally, it looks for a country code of 4, and checks for the text "TMR SEGA" in the header area of the ROM.

The Japanese SMS BIOS (or Mark III BIOS) doesn't check for any of these things, and as such Japanese games may not have a valid checksum, etc. (SG1000 and SC3000 games don't, either.) You can get around this by installing a Japanese BIOS in your SMS, or by patching the ROM, as the SMSWRITE utility does by default.

How about compatibility? Which games work on what machines?

Here's a brief list. Note: "SMS" assumes that the ROM has been patched with correct header information.

SG1000/SC3000 ROMs
SG1000, Othello Multi Vision, SC3000, Dyna, Mark III, SMS, SMS II, Game Gear (GG has partial compatibility only; palette is incorrect)
Mark III, SMS, SMS II, Mega Drive/Genesis (I, II, WonderMega/X'Eye, MultiMega/CDX), Game Gear
Game Gear ROMs
Game Gear

* includes those Game Gear ROMs which use the SMS graphics mode.

What about Colecovision, Atari, Vectrex, Commodore...

It should be fairly straightforward to add support for other 8-bit systems' cartridges, but I don't have plans to do so at the moment. (I would very much like a rewritable Vectrex cartridge, though, so it may happen sooner rather than later!)

Hang on - aren't you encouraging piracy? Copying cartridges is wrong and illegal!

Aside from the fact that it is "fair use" to make backup copies of software you own, reading SMS cartridges and making them available on the internet is a completely different kettle of fish from commercial piracy of current software. The cartridges are no longer manufactured, so Sega are not at any disadvantage if the ROMs are distributed free for everyone to enjoy.

I think there's a more important factor, and that is the issue of ''' preservation'''. Video games are part of our cultural heritage, and it's very important that they are preserved and archived for the benefit of future generations. Experience has shown that rights holders do not always look after historical material properly, and fans and enthusiasts must seize the initiative themselves - even if their actions are nominally illegal. Two examples:

The video game industry is more disdainful of its past than any other, and that' s why it's so important that their products are archived by fans and kept for posterity. (And if you continue to play and enjoy the games via emulation, so much the better!) Additionally, it frees the games from the elitism of the " collector's" market - as a comparison, imagine if the only way you could enjoy the Beatles' music was by paying hundreds of pounds/dollars for original 1960s vinyl albums! If you still think it's wrong, and choose to follow the industry propaganda on this issue, then I'm afraid we'll have to agree to disagree.

< Guide To Responsible Dumping | SMSReader | Acknowledgements >

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Page last modified on Fri Sep 30, 2011 9:13 am