Need advice on Creating rewritable cartridge - Flash - Eprom

[rewritablecartridge]

I am working on creating a rewritable Master System/Game Gear cartridge based on information found on http://cgfm2.emuviews.com/smsflash.php.

This is basically a mod on the game Phantasy Star. I bought a Willem Eprom programmer (which I don't recommend ANYONE to buy as mine is very buggy) to do the Flash memory programming. The question that I have for "The Experts" is do I need some sort of software to convert the .gg or .sms roms to a .bin format or can I just rename the extension to .bin and write to the flash memory?

I know in the Sega Genesis world, raphnet created a tool call smd2bin for his rewritable genesis cartridge (his cartridge is AWESOME!!) which converts the .smd format to a .bin format. His website is http://www.raphnet.net/electronique/...is_cart_en.php

Any help you can provide would be GREATLY appreciated!

Thanks!

 

[ExCyber]

I don't think there are too many problems with SMS images, although it's been a while since I've looked at them. Most of the weirdness in Genesis images is related to the 16-bit bus. The main things I can think of would be:

1) Make sure there's no copier header on the image (i.e. your image's size in bytes should be an exact power of two such as 32768, 65536, 131072, 262144, 524288)

2) If the game is smaller than the flash you're putting it on, you might want to duplicate it so that it's mirrored throughout the flash, e.g. with a command line like (supposing a 128KB image and 512KB flash chip):

copy /b 128k-rom.bin+128k-rom.bin+128k-rom.bin+128k-rom.bin 512k-rom.bin

 

[rewritablecartridge]

Thanks for the quick reply and information. I really appreciate it!