Genesis Repros?

[bartre]

well, i've made a couple of NES repros, and about 50 snes repros for myself and friends, so i figured i'd move on to the next logical step.
the first thing i've got a question about is what i need to do with the rom image before i burn it to a chip. i know that when i do it for an nes or snes game i have to remove the header, is that all i have to do for a genesis game?

also, i've been looking at some info i found for the wiring of these games, and i can use these chips, depending on the size of the game:
Eprom 27C400 = 512KB
Eprom 27C800 = 1MB
Eprom 27C160 = 2MB
Eprom 27C322 = 4MB

also, how do i figure out which points i need to rewire?

[alexis524]

if you by chance are thinking of doing monsterland IV, lemme know. God i love that game and the entire wonderboy series as whole...

[jeffro11]

Find a pinout for the roms used in the games, then rewire it based on the pinout from your new eproms.

http://nintendoallstars.w.interia.pl/romlab/segalab.htm

Your rom must be in binary form (.bin)

Genesis roms are 16bit. You can use 8bit chips, but you MUST use TWO of them to be equal to ONE 16bit chip. One with the low bytes, one with the high bytes.

Easiest way to use a 16bit chip so you dont need to screw around with two chips.


Keep in mind you can fit 512kb of 16bit data on a M27C800 or you can fit 1Mb of 8bit data.

[Hobie-wan]

You could see if Electrochip on here will give you some pointers. He's made some nice repros of Genesis carts.

[Ziggy]

Easiest way to use a 16bit chip so you dont need to screw around with two chips.

Definitely. Don't use two 8-bit chips. That's just a waste of time and work, and what a hassle trying to fit that mess inside a cart. 16-bit EPROMs are pretty much a direct replacement for Genesis mask ROMs.

[bartre]

You could see if Electrochip on here will give you some pointers. He's made some nice repros of Genesis carts.

that was actually the first thing i did, never got any kind of a response, even when i asked to straight buy the carts.

also, the first game i want to make is Mega Man the Wily Wars
if i'm correct, i can use an M27c160 chip as a direct replacement on an NBA Action 94 cart, provided i use the SRAM/region patch on romhacking.net for the rom.
what do i need to do to the rom in before i burn it to the chip?
i took the base rom, applied the patch, and fixed the rom's checksum. is there a header or anything that i need to delete?

[Ziggy]

that was actually the first thing i did, never got any kind of a response, even when i asked to straight buy the carts.

I kinda frown upon him anyway. Almost ALL of his posts on this forum are in the B/S/T forum, tells me he's just here to make money. No doubt he found this forum from my repro thread (that thread always comes up and one of the first few hits) and decided to join up and spam his repros here.

what do i need to do to the rom in before i burn it to the chip?

Genesis ROMs don't have headers that you have to remove like SNES or NES ROMs do. The only thing you have to do is a 'swap byte' before you burn (this function should be in your programmer's software).

[bartre]

well, the thing is i don't have a programmer, i order all the chips preprogrammed from hobby roms.
thanks for that, do you know of any tool that can just do the swap byte function?

[Ziggy]

You might be able to download the software for a programmer, load the ROM up, perform a swap byte, then save the ROM. Otherwise, I'm sure Hobby ROMs would be able to do it for you.