It is currently Sun Dec 10, 2017 7:26 pm

All times are UTC - 7 hours





Post new topic Reply to topic  [ 1 post ] 
Author Message
PostPosted: Wed Jan 18, 2006 8:25 pm 
Offline

Joined: Wed Jul 13, 2005 3:14 pm
Posts: 356
When dumping my carts, I ran into 1 case where an SxROM cart did not dump properly. The game is "All-Pro Basketball" which is 128K PRG and 128K CHR. When I would try to dump this cart, it would only dump a 32K PRG ROM.

The reason this would happen is because the ROM has an unusual layout where the 2nd bank is a copy of the 1st bank and then the 3rd and 4th being different data. This causes the size detection routine to think it's looking at mirrored data so it stops after the 1st bank.

I got around this by forcing the plugin to skip the PRG size detection and to just dump 128K.

You could implement this generically, but I don't think pros outweigh the cons. You would have to change the plugin so it CRC'd to the max ROM size on the cart just to make sure there isn't more valid data. But this would kinda suck because doing a CRC on PRG banks is a relatively long operation and this would add quite a bit to the time it takes to dump a cart. Plus pretty much any plugin could be susceptible to this problem so to be 100% safe you would have to add this kind of behaviour to other plugins as well.

I think a better solution would be a way to override the size detection routines in the rare case it's neccessary. This would require changes to the BIOS as well though.

So just letting people know to keep their eyes open for things like this. If you have a cart your having trouble with and are unable to customize a plugin for it, feel free to ask and I'll help out if I can.


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 1 post ] 

All times are UTC - 7 hours


Who is online

Users browsing this forum: Bing [Bot] and 7 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group