GSOD when power-cycling

Discuss hardware-related topics, such as development cartridges, CopyNES, PowerPak, EPROMs, or whatever.

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Kreese
Posts: 65
Joined: Sat Sep 22, 2007 3:42 pm

Post by Kreese »

Hello guys! Here is another newbie question...

I have made some carts using different size for PRG and CHR eproms. 128kbit and 256kbit. The PRG eprom is 32Kb (256 Kbit) and nothing strange about that.

But a friend of mine told me that if I have a CHR file that is smaller than the actual eprom, I have to "double it up". I've done this in a HEXeditor, and then I've put the CHR-file on eprom.

When trying the eproms in my test cart, I sometimes get a grey screen when turning the power on and off. The program works all the time though. So I was thinking that I was doing something wrong "doubleing" the CHR file up... Is it just to copy all data, go up to the start of the file, paste it in?

Anyway, the cart works fine everytime I have the power turned off for at least 10 seconds and then turning it on. But Turning it on/off fast makes this problem occur... Hmm...
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koitsu
Posts: 4203
Joined: Sun Sep 19, 2004 9:28 pm
Location: A world gone mad

Post by koitsu »

You should start a new topic about this issue in the NES Hardware and Flash Equipment forum, not a follow-up to this thread.
3gengames
Formerly 65024U
Posts: 2281
Joined: Sat Mar 27, 2010 12:57 pm

Post by 3gengames »

You need my ReadNES2 character separator:


http://aaronrls01.webs.com/Etc/ReadNES2.zip


Change the batch file with the .NES file's name, and when you run it, it makes 2 .BIN files to put on your roms.


Haha notepad.....your crazy! XD


Edit:

Is it that when it boots up the ROM's are in the right bank because there's no power on the bank selection pin? And when power gets turned off the console pulls the pin high somehow?
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Kreese
Posts: 65
Joined: Sat Sep 22, 2007 3:42 pm

Post by Kreese »

Sorry for not starting my own thread!

I'll explain my problem more detailed:

First of all, I have made a NES-rom using NO-CARRIERs VegaPlay.

Then I used caJones to split up the rom-file to a .PRG and a .CHR file. The PRG-file is 32 Kb and the CHR file is 8 Kb.

To fill out the 128kbit eproms (and 256kbit eproms) that I use for the CHR data i've doubled the information by copy the CHR data twice in a HEXeditor. By doing that the CHR-file gets the right size (16kb/128kbit). When uing 256kbit eproms I've doubled the 16kb CHR file once again, so it's 32kb.

When inserting the carts that I've made, everything works fine. I press the powerbutton and "VegaPlay" starts to play the songs. The graphics are shown on the screen.

But if i press Power Off, and then turn it ON fast. The graphics are not shown. It's only grey on the screen. Still the music plays just fine (so the PRG chip works as it should). Soultion: Turn power off, wait 4-5 seconds, turn it on again and it works.

Now to the question, why is this happening? Slow eproms? have I doubled them wrong? It's not a big issue, but I'd be really glad if someone explained why this happens!

//Thanks!
3gengames
Formerly 65024U
Posts: 2281
Joined: Sat Mar 27, 2010 12:57 pm

Post by 3gengames »

You can allways program one bank and pull all pins required high to make sure it doesn't boot up in a random bank, that sound like it could work, like when the MMC boot up from not being completely powered down it doesn't check for the correct bank.
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