OK I know this has probably been covered but I have an NES cart witch was originally a crystalis (US) I removed the mask ROM's and put in a AT29C020 I left WE pin unconnected (because I figure I don’t have to write to it so that’s ok?) and the OE connected to ground everything else is connected to its counterpart sept the no connection pin on the chip and extra CE on the board (pin 2)
I have Project Q (J) loaded into the flash to test it
I put the board into my game genie so I do not have to reassemble the cartridge and plug it into the NES I get past the GG screen the game starts sound and everything is working fine sept video is doing that blocky white thing were you can almost make out the picture
What am I doing wrong?
I actually remember reading how to fix this 2 years ago but cant remember/find it sorry for my foolishness
edit:tryed connecting WE to 5v but that did not change anything
Edit2: also tried soldering OE directly to pin 14 on the mmc3 as someone suggested it would be a good place for it, but same result as ground
Edit3:I tryed a differint game as a test Shaffle Fight (J) same resolt. Now im out of ideas and am going to bed if some knows what I need to correct please do tell
edit:4 tryed it without the GG STILL not working
peppers wrote:
the game starts sound and everything is working fine sept video is doing that blocky white thing were you can almost make out the picture
Sounds like an error in the CHR wiring. Can you take a photo of your TV or a TV-in screenshot while your NES is misbehaving?
Did you replace BOTH chips (PRG and CHR) ?
Did you tie WE high to BOTH chips ?
Did you apply the rewiring needed because Nintendo mask roms have a slightly different pinout (I guess the modifications for 27C20 also applies to 29F20, the only difference is the WE pin instead of VPP, because writing to an EPROM is obviously impossible, and a Flashrom doesn't need any other supply than VCC).
Did you connect /OE of the PRGROM to ground, and /OE of CHRROM to the cartridge CHR /RD signal (actually there is no /OE driven by the MMC3 as you seems to mention) ?
Did you connect /CE of the PRGROM to pin 14 of the MMC3 (NOT /OE) and /CE of the CHRROM to cartridge CHR A13 signal ?
so far I have onley put the PRG ROM in and the 2 games I mentioned I am useing to test my work have no CHR ROM so I just removed the stock one for now, that ok right?
ill let me get my Vid capture card to take a photo and have one soon
This is what I did the first time around and get no differint resolts with outher things I have tryed so far, if nothing is wrong is thery I am just going to redo my wireing sence I did most of it a few years back and now I am much more skillfull I assume its not due to the /CE on "pad" 2 on the board not being connect to anything
vid cap is MIA but here is Shaffle Fight's title screen with webcam, please check the post directley above this one and tell me is everything is correct, if yes I will redo my soldering
That looks like you got some of the data lines mixed up with the address lines.
could and tell me is this is correect? if I understand correctley none of the data lines change from the mask, thank you
http://img504.imageshack.us/img504/753/ ... herxv1.png
My lists show Crystalis has 128KB of chrrom, but Project Q (j) needs 8KB chrram. You will have to solder in a ram chip like a 6264. Will also need to add the chr /wr signal because the crystalis board is unlikey to have it.
If the game is running and you get sounds the prg wiring is probably all correct.
Then you should follow the TKROM -> TNROM conversion listed
here.
More on the same topic, Shaffle Fight also needs chrRAM. If the rom file doesnt have a chr section, it needs a ram chip.
oww I get it if the game has no CHR rom then it must have a ram chip in its place? ok now it makes sence
they are always 8kb?
if thats the case then no problem, thanks loads guys
too bad for me I did not read that before I desoldered my socket I knew I missed something I assumed the nes could access the PPU with internal RAM
OK I have one more question TKROM-01 board
is there any additanal connections I must change when the orginal had a 128k and I want a 256k in there
I ask because I did it normally following
this and I get a lot more color but still not correct its like solid colors with white and black lines with a few game colors showing
although the socket I am useing could be to blaim as its not in great condition
the orginal game had a 128K CHR I now want to put a 256k I followed the trace from pin1 to pin 12 (chr A17) on the mmc3 so everything is correct, at least all the addresses seem to be
edit:removed socket soldered in chip directley same problem
new title image of earthbound as test with 256k chr rom
problem described in directley above post
Normally the EPROM conversion described applies for the maximum ROM size available for the mappers, and some rewiring can be skipped if you know what you do (for example if you have 128k instead of 256k you don't need to rewire A17).
This shouldn't cause you problems. Make sure you get all CHR rewiring correctly (use a ohm-meter or short-meter).
All my connections are good and my program is correct I erased the first 16 bytes then in this case split it in half leavening me with 2 files consisting of 262,144 bytes each my Willem verifies the code is correct
I have soldered it 3 times checked and rechecked my connections at first I was using 30awg wire but replaced it with much thicker wire I do not know what could be wrong tried everything I could think
problem SOLVED! I connected WE to 5V on the CHR but not on the prg and now it works just fine
why is that?
or I also kept messing with pin a16 on the chr till it broke and had to solder to tiny bit of pin left and perhaps that somehow did it but I dout it sence I resoldered it meny times and there is not much chance I would have screwed that one up every time (i have outher flashroms around I will use when I get real this is just a test for me)
I do not know why its now working but I am glad feel free to tell me that I did right if you like.
Now if I can just find the top half of the cart I put somewere 2 years ago when I started this and just now gotten around to finishing it,