It is currently Wed Oct 17, 2018 4:34 pm

All times are UTC - 7 hours





Post new topic Reply to topic  [ 8 posts ] 
Author Message
 Post subject: eprom programmer broke??
PostPosted: Wed Feb 01, 2006 6:09 pm 
Offline

Joined: Sat Sep 17, 2005 12:26 pm
Posts: 278
so lately when trying to make dev carts, they have all been playable, but scrambled. I know it is not the wiring because it is happening to the NROM and CNROM games. is it my programmer? i have made many carts before with no problems, could it be dust getting in the programmer or something like that? any help would be great.


Top
 Profile  
 
 Post subject:
PostPosted: Wed Feb 01, 2006 6:49 pm 
Offline
Site Admin
User avatar

Joined: Mon Sep 20, 2004 6:04 am
Posts: 3569
Location: Indianapolis
Do you verify them after programming? If it's not crashing then I'd guess the PRG ROM is fine and it must be the CHR or mirroring.

If it's an EPROM on the willem burner, make sure the VPP jumper is at the right voltage. I had the wrong voltage when burning an OTP EPROM before, and the data came out with some corruption. That was apparant as soon as it tried to verify it though.


Top
 Profile  
 
 Post subject:
PostPosted: Thu Feb 02, 2006 4:05 am 
Offline

Joined: Sat Sep 17, 2005 12:26 pm
Posts: 278
how do you verify after programming? yea, it has to be the chr eprom since all the games work fine, but the graphics are messed up.


Top
 Profile  
 
 Post subject:
PostPosted: Thu Feb 02, 2006 7:31 am 
Offline

Joined: Mon Jan 02, 2006 6:30 pm
Posts: 53
coinheaven wrote:
how do you verify after programming? yea, it has to be the chr eprom since all the games work fine, but the graphics are messed up.


($0.02)

Just a thought: have you tried swapping and programming your eeproms (use the PRG eeprom for CHR and vice-versa) to see if its the one chip that is bad? If you get the same results, then its not a problem with the programmer.

Also, (and I'm probably being dense about this) how do you know that the PRG ROM is okay if you're getting scrambled graphics? Maybe the PRG ROM is just a little less scambled, which would still implicate your programmer.

Also, don't forget the simple stuff! We've all seen this with standard carts in our toaster-loaders - you could just have dirty contacts on just the CHR ROM pins.


Top
 Profile  
 
 Post subject:
PostPosted: Thu Feb 02, 2006 11:23 am 
Offline
Site Admin
User avatar

Joined: Mon Sep 20, 2004 6:04 am
Posts: 3569
Location: Indianapolis
coinheaven wrote:
how do you verify after programming? yea, it has to be the chr eprom since all the games work fine, but the graphics are messed up.


Using the willem burner I think it does by default after programming (though there might be a way to disable it). The way to check it manually is to load the data that should be in there, put the chip in the socket, then go to Action / Compare/verify. If it verifies OK then it probably is the cart contacts or something.


Top
 Profile  
 
 Post subject:
PostPosted: Thu Feb 02, 2006 12:08 pm 
Offline

Joined: Sat Sep 17, 2005 12:26 pm
Posts: 278
i just remembered i moved my computer desk about a month ago and the programmer fell off, i wonder if that did something. i didnt think anything of it at the time, but that might have done something. i just cant remember if this problem started after it fell off. but i always make sure that the eprom is verified or i dont use it. if something was wrong with the programmer would it still verify and say it programmed the chip correctly? i would think if something was wrong it would not work at all. hmm, ill have to inspect the programmer to see if anything was damaged.


Top
 Profile  
 
 Post subject:
PostPosted: Thu Feb 02, 2006 12:53 pm 
Offline

Joined: Sun Sep 19, 2004 11:12 pm
Posts: 20662
Location: NE Indiana, USA (NTSC)
coinheaven wrote:
how do you verify after programming?

Can you make a crc routine that reads from $2007?


Top
 Profile  
 
 Post subject:
PostPosted: Thu Feb 02, 2006 1:15 pm 
Offline
Site Admin
User avatar

Joined: Mon Sep 20, 2004 6:04 am
Posts: 3569
Location: Indianapolis
Yeah, if something was wrong with the programmer it probably wouldn't work at all (or would at least fail verifying).


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 8 posts ] 

All times are UTC - 7 hours


Who is online

Users browsing this forum: tokumaru and 4 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