Hello There!

I'm planning some voodoo with NES roms :-)

My victim will be Gyruss (CNROM, right?!)
I have an CNROM Arkanoid cartridge that uses EPROMS, so It will be easy to do. But Wait: the guys at ROMLAB says Arkanoid is "NROM" (smb, etc...). However in http://www.parodius.com/~veilleux/boardtable.txt we have a doc that says Arkanoid is "CNROM". :-?

What is right?! Or is it the same thing???


Thanks to Ya, amazing crowd!!!

If you have the cartridge then look yourself. You will find CNROM somewhere on the PCB if it is a CNROM.

Any NROM program will work on a CNROM board; you'll just have to either use smaller EPROMs or fill the EPROMs with multiple copies of the CHR. Perhaps they just had a surplus of CNROM boards during that particular manufacturing run.

Well I'd do it, but it's a pirate copy of Arkanoid, with EPROMS and LS161. So, it doesn't have any mention to board version. :-(

I think 27C256Q for PRG data, and a 27128AD for CHR...

I have some EPROM facilities and I'll try to put Gyruss and Castlevania 2 on carts (of course, Castle 2 will need another kind of hack). Will it work???
:-o


Regards

to tepples: thanks for the advice, but what I want is just the inverse way:
to put a CNROM game on a NROM board. My board (arkanoid NROM) is filled with EPROMS, and I want to substitute them for burned EPROMS with Gyruss (CNROM).

My question is about the so called "bankswitching". NROMS doesn't have bankswitching and CNROMS have it.

Thanks

> but it's a pirate copy of Arkanoid, with EPROMS and LS161

Then it's almost definitely CNROM

> 27C256Q for PRG data, and a 27128AD for CHR...

It *is* CNROM - NROM can only handle 64kbits of CHR data, and this one has 128kbits.

--
Quietust
P.S. If you don't get this note, let me know and I'll write you another.

quietust: but how arkanoid could be placed on a CNROM cart? Isn't it a NROM game?

NROM games can run on CNROM with no problem.

But if the boardlist.txt file says it's CNROM, I'd tend to believe it. If the CHR-ROM is larger than 8Kbytes (sounds like it is), it has to CNROM.

If memory serves, arkanoid is CNROM, which has an additional 74ls161 to do address switching of the larger program ROMS.

If you are making a devcart, it is better to do it with a CNROM board, since with a mirroring switch/jumper and smart ROM burning, you can put any NROM/CNROM game on it.

Since english is not my natural language, I think I'm having problems with my question... :-(

Please, I DO KNOW that a NROM game can be placed on a CNROM board. Thanks a lot.

But the question IS: CAN I PUT A CNROM GAME IN A NROM BOARD?????????

philtulju gets the point, since he speak about some kind of "jumper" in order to select what game it will use (kind a "universal board").

Maybe someone have an idea or schematic about this task, in order to put the LS161 on the board (I'm using common EPROMS, not the original ICs)

Thanks a lot for the attention and sorry for be misunderstood. :-)

> But the question IS: CAN I PUT A CNROM GAME IN A NROM BOARD?

No, you can NOT put a CNROM game on an NROM board.

> philtulju gets the point, since he speak about some kind of "jumper" in order to select what game it will use (kind a "universal board").

Actually, he was speaking about using a jumper to select MIRRORING, which is totally different (varies from game to game, generally based on which way the game scrolls).

--
Quietust
P.S. If you don't get this note, let me know and I'll write you another.

Since your pirate cart already has a 74ls161, is is probably effectively a CNROM board already, so it should work with any NROM or CNROM game; just fill up the EEPROMS with the data several times over if the game PRG or CHR is too small to fill up the chip.

eheheh!!! Thanx quietust! :-\

words by philtulju: "(...) since with a mirroring switch/jumper and smart ROM burning, you can put any NROM/CNROM game on it".

I didn't repair in the word "mirroring". Sorry for any inconvenience! :-(

______

One last question: supposing I'll go to work a NROM game, I've noted that exist some "sub-models" of the same board (NES-NROM-[01,03,05]). Does this makes any diference? (wiring, IC models / numbers, pins...)

Cheers