Hello guys,
i'm trying to figure it out if that's possible to use 27C040 eproms instead of 27C080/27C801 for making small repro carts that need 1MB or less roms like Zelda lttp or nightmare busters.
I've go a lot of this eprom taked fro dead jamma arcade boards.
I've splitted the files in 2 parts, as they can fill up only to 512KB each and deleted the headers from the parts. ByteSwap is not needed (right?)
So when i need to match the pins i've figure it out that 27C040 missing A19 Adress pins and they have instead a Vpp adress (wich is...? +5V?)
Do the mask rom realy need that adress in order to work? I now can sound dumb but i'm in the middle of knowledge with this stuff, know some, not all.
Maybe i've stack up the splitted eproms incorrecly? Does the first eprom goes up or down the second one?
Thank you for your help, i'm so close to understand this and i would like to have/play my nightmare buster cartridge..
i'm trying to figure it out if that's possible to use 27C040 eproms instead of 27C080/27C801 for making small repro carts that need 1MB or less roms like Zelda lttp or nightmare busters.
I've go a lot of this eprom taked fro dead jamma arcade boards.
I've splitted the files in 2 parts, as they can fill up only to 512KB each and deleted the headers from the parts. ByteSwap is not needed (right?)
So when i need to match the pins i've figure it out that 27C040 missing A19 Adress pins and they have instead a Vpp adress (wich is...? +5V?)
Do the mask rom realy need that adress in order to work? I now can sound dumb but i'm in the middle of knowledge with this stuff, know some, not all.
Maybe i've stack up the splitted eproms incorrecly? Does the first eprom goes up or down the second one?
Thank you for your help, i'm so close to understand this and i would like to have/play my nightmare buster cartridge..