0 chr?

hayabusa_fmw

what does 0 chr mean when you are reproducing a cart or reparing one with a faulty rom?

this means it needs to be a blank chip with no info on it????



what is the usage of that? 

MrPete1985

I think that it means it is a RAM chip, what app are you using to give you the info?

hayabusa_fmw

Famirom

nesmapper



let's give random game like megaman 2 for example



it's a 512kb prg i think with 0 chr this means a 0kb chip = blank = erased?

MrPete1985

Just loaded MM2 into NESTopia, it uses CHR RAM not CHR ROM so it is a 8k RAM chip, not sure if it is SRAM or some special kind of RAM



NESCartDB also confirms it

http://bootgod.dyndns.org:7777/pcb.php?search=NES-SGROM&treehead=producer&PcbID=414



File: Mega Man 2 (U).nes

Directory: C:\Users\Pete\Desktop\

Soft-patched: No

CRC: 0FCFC04D

SHA-1: 2EC08F9341003DED125458DF8697CA5EF09D2209

System: NES-NTSC

Board: NES-SGROM, Mapper 1

PRG-ROM: 256k

V-RAM: 8k

Chips: MMC1B2

Battery: No

Dump: OK

hayabusa_fmw

ok and for all games using chr ram it's not ''burnable to eprom?''

Lincoln

when famirom says 0 chr it's tell you there is no chr file in the rom.



when making games that use chr-ram, you replace the prg chip and leave the ram chip alone.

hayabusa_fmw

ah ok gotcha



I had a mmc1 board laying with an old project of mine i did years ago.I don't know which size chr , so i checked for megaman in a mapper list and i saw 0 and told myself how the hell could this be possible.

I guess you need a donor with a chr ram already am i correct?

MrPete1985

That's how most do it, I think it might just be SRAM, not sure though, you could try looking up the part number printed on the chip.

hayabusa_fmw

interesting , cause i know that the ''point'' of making reproductions are to match the eproms pinout with the original game one so this is why most need wires.

when i saw 0kb i told myself ok what ever happens if i want to test something like that? im screwed. If someone does a repro-hack or mm2 that uses mmc1 that will cause headache

hayabusa_fmw

chr-ram it is ...

Guntz

Umm, MegaMan 2 already uses MMC1. Its board type is SGROM, meaning it uses 32pin PRG ROM, CHR RAM, MMC1, no PRG RAM or a battery circuit.



Nearly all MM2 hacks in existence use SNROM, meaning they use 32pin PRG ROM, CHR RAM, PRG RAM and a battery circuit (probably goes unused most of the time).

Lincoln

Originally posted by: hayabusa_fmw



ah ok gotcha



I had a mmc1 board laying with an old project of mine i did years ago.I don't know which size chr , so i checked for megaman in a mapper list and i saw 0 and told myself how the hell could this be possible.

I guess you need a donor with a chr ram already am i correct?

that's the easy way to do it. there are some more involved hacks that combine chr-ram with mappers for which there is no existing donor. in that case you have to install a ram chip in place of the original chr mask rom. it's doable but requires wires.

hayabusa_fmw

I found a chr ram from pro am II this should be a direct fit if im not mistaking??

Lincoln

you're going to use rc pro am ii as a donor? why?

hayabusa_fmw

I have it in double and i had a bad rc pro am (removed / no label ) marker on it. this is why

Lincoln

pro am ii without a label is still more valuable than a throwaway donor.



what donor do you need? or what rom are you trying to use?

hayabusa_fmw

Im trying to get back my dead megaman 2 cart or maybe some hack of it. The original cost too much for me locally.



i seem to have all the tools for it im sure i would enjoy it as much as i enjoy pro am II



I have a 29f040 chip ready for it. it's just im confused on how i need to do this i used to do it by following nes dev's forum but like i said this was like 5-6 years ago .

I don't recall if i need to check pinouts and turn my 29f040 to the original pinout? or vice versa.



also since the file was originally 256kb but i doubled it to fill the chip is it now a 512kb pinout????



and also i want to get back to reproductions cart as a hobby but like i said im confused to the point as i don't know much of what im doing.

Lincoln

how is your mm2 cart dead?



are you just putting an mm2 rom on a donor board? rc pro am 2 is not a compatible donor. here is a list of compatible boards: http://bootgod.dyndns.org:7777/search.php?keywords=&unif=NES-SGROM&field=1&order=desc

in most cases famirom will tell you the class(es) of board that support your rom.



follow the regular instructions for prg and you should be fine.

hayabusa_fmw

Donor im using : mmc1 cart u4mmc1 which is exactly what mm2 uses

Donor for chr ram chip : from rad racer II it's just ram thats it? of what i heard?



Following the prg chart if i got this correctly tell me if i do

for a 29f040 eprom to 256 prg i would need to do the following



Pin 1 to hole 30



hole 2 to 22 together



24 to hole pin 2



hole 30 to pin 1



pin 32 and 32 soldered bridged as 5 volt (on board) since 32 is supposed to be 5v



thanks for the help im not the clearest guy to respond to lol sometimes i read myself and im like jesus christ wtf am i talking about?

Lincoln

dude I don't know what you are talking about. rc pro am II is not a mmc1 cart. rad racer II is not a mmc1 cart. you should get a mmc1 cart with chr-ram already installed- SGROM or SN. if you use SL or SK you have to jumper some pins on the chr-ram to make it work. one of those goes to one of the pins on the cart connector, which may not be there on SL or SK boards, meaning it's not going to work.



for installing 256K or 512K chip with a double rom its

pin 1 up

pin 2 -> hole 24

pin 24 -> pin 16/other GND point

pin 30 -> hole 1

hayabusa_fmw

I said i have a mmc1 board but i could use the chr-ram chip from pro am ii

The mmc1 board i had laying isnt a chr-ram

But a chr-rom





Sorry for the confusion

Lincoln

probably not going to work, mmc1 boards without chr-ram are missing a pin on the edge.

Guntz

Please don't kill a Pro AM II cart for it's RAM chip, that's an off-the-shelf part can can easily be bought from numerous IC sellers.



Perhaps I can help? I can solder cartridges and I'm in Canada too, cheap shipping. What is it you want done? You say MM2 is dead, in what way? Does it not boot? Are the graphics a mess? Help us help you.

hayabusa_fmw

Rc pro am will be saved guys!

hayabusa_fmw

Can you guys teach me the best way to make a label to restore it?