Rom burning

[Kaneda]

If i want to burn a game on a cartrige...what model of rom (eprom/eeprom/flash...) i need ? I think about replace existing rom of a low cost Genny game (Fifa, etc..)

I ask because i need to buy a Eprom Burner to repair my arcade PCBs and I would like to choose a model useful for my little genny too!

Kaneda

 

[Arakon]

first of all, you usually can't simply burn a rom and pop it in, the pinout is different for the most part, except for some that require 42 pin eproms, which are hard to find and way expensive. second, you'll have a very hard time finding 16-24 mbit eproms.

the easiest way is to take apart a bootleg cart, cause those usually use normal eproms, but you'll have to split up the romfile to work, usually into odd and even bytes.

 

[Kaneda]

Originally posted by Arakon@Jun 9, 2004 @ 12:30 PM

first of all, you usually can't simply burn a rom and pop it in, the pinout is different for the most part,

well..for SIMPLE game, you just need 2 eproms and connect Genny A1-> Rom A0, etc.. no ?

I say that looking at DevSter's work

except for some that require 42 pin eproms, which are hard to find and way expensive. second, you'll have a very hard time finding 16-24 mbit eproms.

it's my question...

i don't know how to "choose" a eprom...

If i find a eprom seller, what i must know ?

i talk about voltage, speed, power, ....

if i know that, i can then list the compatible eproms and so choose my programmer

the easiest way is to take apart a bootleg cart, cause those usually use normal eproms, but you'll have to split up the romfile to work, usually into odd and even bytes.

yes : i almost finish my rom splitter....

Kaneda

 

[Kaneda]

It seems i find a usefull info

now i need to know what is the minimal specification needed about power and speed (70ns?)

+ tell me if i'm wrong but i can also use full 16bits roms ? like a 256k x 16 no ?

and so, no problem with odd/even

oh my....my electronic learning is soooooooooooo far!

 

[Arakon]

16 bit eproms will let you put a full game on it (i.e. MUSHA works fine on a 4 mbit 16 bit eprom).

small games will work fine like that, it gets problematic (kinda) when it comes to games over 8 mbit.

as for the speed, just about any will do, I've used up to 200 ns slow eproms just fine.

for the voltages, that's a standard.. they run on 5V.

FYI:

http://arakon.dyndns.org/cartsfront.jpg

http://arakon.dyndns.org/cartsback.jpg

those are the 2 carts I made a long time ago (they even work for 32X, btw).. unfortunately I no longer have the documentation or tools to split the roms.

obviously, games that need sram won't be able to save on these.. but I also have a wonderboy IV cart that was made from a FIFA cart with sram, which plays and saves great.. it uses a 42 pin 16 mbit eprom, no idea where the guy got it from.. most eprom programmers will only do 32 pin 8 bit eproms, the more expensive ones, or with an adapter, will do 40 pin 16 bit eproms too.

 

[Kaneda]

as my goal is more to make a "real" cart of my demos than burn full game, a 'little' eproms (x8 or x16) will be enought

for the save, i'll see later

so a standard eprom programmer like thiswill do...as long as it has 32 pins

Thanks a lot!!!

Kaneda

PS: For people who want to know more, i think you should read this

PPS: to the mod, i hope all these links don't disturb ?

 

[Arakon]

I recommend looking into the willems programmer, it's a lot cheaper (especially when you choose to put it together yourself) and there's a load of (also cheaper and/or selfbuild) adapters for it too.

 

[Kaneda]

yes...i saw a lot of them on ebay..

but there is so many models!!!

an additional note, why a lot of eproms need a 0.1µF on the VCC ?

how do i know if i need it or no (i read datasheet who talk about and others who don't) ?

 

[Arakon]

that capacitor is just for filtering purposes, and not really necessary in most cases.. the genesis provides a pretty stable voltage.

 

[Kaneda]

Ok...just for safety so...

thanks