ok whats wrong with my MMC3 dev cart

ok whats wrong with my MMC3 dev cart
by peppers on 2005-10-21 (#5745)

OK so far I have replaced the PRG rom in "Crysalis" with the 256k flashrom "Pm29F002T-12PC" witch is very simmaler to a 29F020

the onley pins I left unconnected is WE# and OE# everything else is connected to its maching place on the board

I have cut out the CHR rom but have yet to desoder the pins from the rom witch was on there

as a test I have tryed loading a rom image of the japanise game "shaffen fight" by eraceing the 16bite header leaveing me with an image just the right size

due to the fact I an unwilling to risk my real nes till I get it working I am useing a crappy noac famiclone called "Game Player" when I try to load the cart all I get is black and afterward it wont run any cart for a wile then it starts working again

by Memblers on 2005-10-22 (#5748)

/WE and /OE are inputs, they need to be connected to something. You could connect /WE to 5V, I'm not sure where to get the /OE on an MMC3 board. I suppose you could connect it to GND.

by peppers on 2005-10-22 (#5750)

alright I will give it a try thanks

by peppers on 2005-10-22 (#5751)

not working

by tepples on 2005-10-22 (#5756)

/OE goes to PRG /OE (pin 14) of the MMC3.

by Guest on 2005-10-22 (#5758)

are you sure? that pin connects to pin 2 of the s-ram

by peppers loged out on 2005-10-22 (#5759)

^ im going by this page
http://www.tripoint.org/kevtris/mappers/mmc3/

sorry I sould sign in
by sorry on 2005-10-22 (#5760)

^for pin number onley I followed the trace to the second pin of the s-ram

by peppers on 2005-10-22 (#5761)

^I was wrong but it dose not seem to be working

im sorry but are you compleatley sure that is how it needs to be wired?

with is WE# connected to vcc and OE# connected to pin 14 on the mapper

if you are I guess it must be the rom I am useing and I will have to order some of a differint type

by Necrosaro420 on 2005-10-22 (#5764)

Why not just get a 27c020?

by peppers on 2005-10-22 (#5765)

they are eproms I do not want to buy a UV lamp

edit:I want ahead and ordered some real 29F020's if they dont work I dont know what to do

by Necrosaro420 on 2005-10-23 (#5789)

peppers wrote:
they are eproms I do not want to buy a UV lamp

edit:I want ahead and ordered some real 29F020's if they dont work I dont know what to do

Well, you DONT have to have a uv lamp, just hope the burn works correctly and everything is set up right and you are fine

by peppers on 2005-10-23 (#5793)

yes but I intend to program them more than once

by leonk on 2005-10-24 (#5851)

Couple of pointers:

- I'm not familiar with the flash ROM you're using.. just make sure that the specs on it (pinout) match and you'll be find
- don't worry about using it on your real NES. I've never EVER heard of a dev cart killing an NES!

Lastly, some games will not boot correctly if the CHR is missing (as you made it sound).

good luck!

by peppers on 2005-10-26 (#5957)

thanks, actually the game I had loaded into it had no CHR rom I was just saying I cut out the the mask ROM for the CHR but did not desoder the pins from it (none of them are toching)

so now I wait for flashroms to come in unless those 2 pins dont go where I got um