Burning SMS Roms to EPROM


I took a Master System Sonic Cartridge to pieces and desolderen the ROM from the PCB. I tried to read out the ROM with my eprommer but that didn´t worked. Only the first 8K was readable. (why???)

Now I got two eproms HN27C101 and a M27C1001

Could I copy a small game on it and put the Eprom instead of the original ROM on the sonic cartridge?

Are these Eproms pin compatible with the original Roms or will they get blown??

It would be nice to play some ROMZ on an original Master System...

Bye Sheep64
it is possible, however the SMS uses mapper chips on the PCB to address anything above 32 kb.

if the cart only has a single chip, the mapper chip and rom data are integrated into one chip.

what you need is a cart with an external mapper chip, and some rewiring.

with MikeG's help, I managed to turn a Monopoly cart into an eprom cart with saveram, which even plays Phantasy Star 1 perfectly, as well as any demos and tools.

you can find some good info here:

Thanks for that info Arakon!

I´m referering to that site I found under your link.


There they use a cartride "World Grand Prix"

I opened my After Burner cart and found the mapper and the ROM chip. I noticed that the ROM chip in Afterburner has the same number of pins like my 27C1001 Eprom. So, can I easyly replace the ROM with the eprom? Without modifying the PCB?

I coudn´t read out the ROM from Afterburner to test coz my #### Epromer went up in smoke :((

I plugged in the ISA cart and a TL497A went up in smoke :((( I´ll replace it Thuseday after the holidays.

Then maybe I can check out the ROM dumping.
Seems that you´re right guys :((

I bought a new TL497A for about 3,50€ plugged in the epromwriter card and it blew up in smoke again :(((

The eprommer is some kind of self build thing I bught from eBay. I was released in a PC magazine and someone build it. It always worked fine..

I have to replace all other CMOS chips and TTL´s maybe that´s the fault.

Too bad that I don´t own shematics of it that would make troubleshooting much easier.
You should probably grab a multimeter and make sure you don't have a power/ground short or a damaged resistor or transistor somewhere. If you're lucky, all your chips are fine and a short/screwed part somewhere is making the TL497 blow itself up by drawing too much current.
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/genesis_cart/genesis_cart_en.php

Any help you can provide would be GREATLY appreciated!

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?

You can write it directly to flash memory.

A long time ago some ROMs were distributed with AFAIK a 256 or 512-byte header. I really doubt they are still in circulation these days. All headerless ROMs will be a multiple of 16K if you need to check.