It is currently Sat Jul 21, 2018 12:38 pm

All times are UTC - 7 hours





Post new topic Reply to topic  [ 8 posts ] 
Author Message
PostPosted: Thu Dec 14, 2017 5:20 pm 
Offline

Joined: Mon Apr 04, 2016 7:59 am
Posts: 32
I have an NTSC prototype of a game that was never released in NTSC countries which came to me chip-only. I want to demonstrate it working in an actual NES when it comes time to sell it. I have dumped it and the dump works on both in emulation and on a real NES.

The thing is, the proto came on a Toshiba TC571001D EPROM, which uses a maskROM pinout as opposed to the usual EPROM pinout (TC571000D - shares the same datasheet). It's a CHR RAM SNROM game so popping this chip into a SNROM cart should be a pretty straight-forward affair... even more so than most protos.

First, I made an adapter so that I could dump it in my EPROM programmer. This worked and resulted in a dump of the games that worked on emulators and original hardware (as mentioned earlier). It worked in the Hi-Def NES too.

Next, I socketed a CHR RAM SNROM board (Shingen the Ruler), made a socketed adapter board, tied the extra pins to their respective highs and lows (as specified in the datasheet for Read mode), and popped it in to an NES. It boots but graphics are garbled and it seems to be on different game screens than it should be (sometimes see a non-garbled face that I should only see after completing a mission).

I dumped my franken-cartridge through my Kazzo and the resulting ROM matches the one I got through the EPROM programmer before (maskROM to EPROM adapter). My cart is definitely working for reading the EPROM. Heck, I can try it back to back with my customized cartridge and the Everdrive N8 and it just doesn't work in my cartridge.

I suspected that I damaged the CHR RAM or something so I popped the original Shingen the Ruler ROM back in the socket and it still works perfectly. I'm at a loss!

Anyone know what would cause this? My next step is to burn an EPROM and see if that works but the exact same contents are already there and confirmed readable in the current configuration so I can't see why that would be any different.


Top
 Profile  
 
PostPosted: Fri Dec 15, 2017 12:50 am 
Offline
User avatar

Joined: Fri Nov 12, 2004 2:49 pm
Posts: 7443
Location: Chexbres, VD, Switzerland
How can we possibly "solve" your problem if we aren't given pictures of the problem ?!

Besides, I had no idea EPROMs with Nintendo's pinout ever existed, this is interesting.


Top
 Profile  
 
PostPosted: Fri Dec 15, 2017 12:50 pm 
Offline
Site Admin
User avatar

Joined: Mon Sep 20, 2004 6:04 am
Posts: 3529
Location: Indianapolis
The pinout, for those wondering, is the same as Nintendo's 128kB chip on the "bottom" 28 pins, but it is still a 32-pin chip. Interesting though.

2 possible issues come to mind as to why this isn't working. First, there are a bunch of MMC1 revisions, and they do have known (and possibly unknown) differences. Find out which MMC1 version the released game uses.

Also could be that data in the battery-backed WRAM is confusing the other game. This is extremely unlikely.. unless the 2 games are by the same developer..! Like the famous Tennis / SMB cart swap trick. Again, I doubt it, but you could test this by clearing RAM using the Kazzo.


Top
 Profile  
 
PostPosted: Fri Dec 15, 2017 4:51 pm 
Offline
User avatar

Joined: Sat Jul 04, 2015 9:58 am
Posts: 738
Location: -29.794229 -55.795374
Seems like something is wrong or bad connected with the CHR RAM.
Since the PRG ROM is fine and there's no CHR ROM, Kazzo will (theorically) dump it just right.
Also, it just needs to copy the PRG ROM and properly build the .nes file for the game to work on emulators.

Please, check the CHR RAM's connections. The IC being bad is a possibility, but not very common.

For SNROM repros I tend to use this schematic, from Enri's Homepage.
Some pictures or schematics of what you had already done can help us to help you too.


Top
 Profile  
 
PostPosted: Mon Dec 25, 2017 1:04 pm 
Offline

Joined: Mon Apr 04, 2016 7:59 am
Posts: 32
I have since programmed my own chip with my dump and it's still garbled. Again, the dump works fine in an emulator and the test NES with an Everdrive. I know that my adapter works because I made the dump through it on a Kazzo and it compared identically to one I made through the programmer (ignoring the header, of course).

Bregalad wrote:
How can we possibly "solve" your problem if we aren't given pictures of the problem ?!

Besides, I had no idea EPROMs with Nintendo's pinout ever existed, this is interesting.

I was asking for broad theories, but thanks for wanting to look at it more closely. :)

Here's an image gallery including some new issues:
https://imgur.com/a/39zPX

Memblers wrote:
The pinout, for those wondering, is the same as Nintendo's 128kB chip on the "bottom" 28 pins, but it is still a 32-pin chip. Interesting though.

2 possible issues come to mind as to why this isn't working. First, there are a bunch of MMC1 revisions, and they do have known (and possibly unknown) differences. Find out which MMC1 version the released game uses.

Also could be that data in the battery-backed WRAM is confusing the other game. This is extremely unlikely.. unless the 2 games are by the same developer..! Like the famous Tennis / SMB cart swap trick. Again, I doubt it, but you could test this by clearing RAM using the Kazzo.

Good idea, but I don't think that's it either. The European release was on an MMC1B3 where I was trying MMC1B2. I had two copies of NES Open Tournament Golf and one of them had MMC3B3 despite none of the BootGod profiles showing this. I socketed it and got no change. :(

I did, however, discover that my test Hi-Def NES-001 has issues. With HDMI I could see a strange flicker on the the left/middle of the title screen that I didn't notice until five minutes after staring but it isn't affected by the different Hi-Def NES phase settings. It kinda looks like the line that can flash on the screen from certain NMI writes, but that's definitely not it: The title screen is corrupted in various places all over when using composite (stable, not flickering). Hi-Def NES looks almost perfect until you finish a round of golf and then the text on the tally screen with Mario is totally garbled. Composite output looks fine there, so it seems that the game looks corrupted in two completely different places when using Hi-Def NES versus composite. I don't have an adapter for my Famicoms and my NES-101 is currently in pieces (jacks removed for an AV Famicom multi-out panel swap). I'll have to throw something together from these parts units around me.

I moved the NES Open Tournament Golf ROM into the MMC1B2 board from Shingen the Ruler and the tally screen no longer corrupts on Hi-Def NES. There's definitely different behavior with this game on one MMC1 revision versus another in this particular system, but Elite was doing the same thing on other systems several months ago so I still hesitate to blame the console. I did notice strange issues with StarTropics last week that may be related to my issues with NES Open Tournament Golf and Elite. More than half the time I would get a blank screen. I'm colorblind and don't recall the color but it seemed grayish. The Everdrive would boot to the menu just fine but show the same blank screen about 2 out of 3 times I booted. I tested again and the real cart seems a little more flakey, like booting one out of 5 times. Before that I believed that the ED was to blame because I already found it problematic with the Hi-Def NES: SMB3 would freeze if left on the map for 15 minutes while the original cart will not. This happened on several NES consoles with Hi-Def NES (I was installing it). Even though the SMB3 ED + Hi-Def NES issue has nothing to do with this particular console, the StarTropics and NES Open Tournament Golf issue do.

This NES-CPU-10 console has the full CIC disable (reset behaves like a Famicom), Blinking Light Win with unused pins removed (CLK, audio/AUX, and CIC), Hi-Def NES, and freshly replaced electrolytic capacitors.


Top
 Profile  
 
PostPosted: Wed Dec 27, 2017 5:33 pm 
Offline

Joined: Mon Jan 23, 2012 11:27 pm
Posts: 147
I had the same problem when I was working on it. EPROM read ok (mostly, had 1 byte that seemed unreliable), worked in emulators, garbled graphics on a real cart. iirc I found a donor cart that used the same mapper revision and branded ram as the official pal release but it didn't help.

I wonder if chip access speed has anything to do with it? Elite is doing some pretty fancy stuff for the graphics, maybe the hardware is a bottleneck.


Top
 Profile  
 
PostPosted: Thu Dec 28, 2017 1:23 am 
Offline
Site Admin
User avatar

Joined: Mon Sep 20, 2004 6:04 am
Posts: 3529
Location: Indianapolis
Wait, is Elite the non-working game? Years ago one of the developers released an NTSC version of the ROM, but apparently it was only tested with NESticle. The graphics are screwed up if you run it on a modern emulator. If that's the ROM you have, then it may be working as expected.

Maybe I misunderstood, but there's that bit if info about Elite, if that helps.


Top
 Profile  
 
PostPosted: Thu Dec 28, 2017 10:58 am 
Offline

Joined: Mon Jan 23, 2012 11:27 pm
Posts: 147
Memblers wrote:
Wait, is Elite the non-working game? Years ago one of the developers released an NTSC version of the ROM, but apparently it was only tested with NESticle. The graphics are screwed up if you run it on a modern emulator. If that's the ROM you have, then it may be working as expected.

Maybe I misunderstood, but there's that bit if info about Elite, if that helps.


it's not that one, it's a legit ntsc elite demo/proto


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: Yahoo [Bot] and 6 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