Which games glitch up on pre 04 motherboards?

Started by Salduchi, May 29, 2019, 07:47:21 am

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Salduchi

I got an old square button famicom recently, and it got me interested in what games have problems running on older Famicom's. So far the only one I know of is Rambo, which I tested and it's a complete mess. Totally garbled. What other games have these issues or similar issues? Crashing? How does the FDS work with these old Famicoms?

P

I'd also like to know this, and if possible more exactly what the causes of the glitch are (CPU? PPU? Other hardware?). There is very little information on this.
Besides the problems with Rambo, Fantasy Zone seems to gradually get more and more corrupted graphics after about 2 minutes of playing (according to a Japanese blog with a 01 unit).

Here is the same blog with a 03 unit. It uses the same CPU (first version) and PPU (revision A), and it has similar modifications on the board (resistor and capacitor). But Rambo and Fantasy Zone both plays alright on it. That sounds like the glitch is not simply a bug in the CPU or PPU at least, and it might not be as simple as pre 04 board problem (although who knows if this one had and was repaired). BTW this 03 unit also has grey controller and RF switch cables, and the cartridge cover is smooth.

UglyJoe

There is an old (and excellent) Iwata Asks article that talks about early Famicom days.  They briefly mention that Baseball was a game that used to glitch out:

https://web.archive.org/web/20101010003952/http://us.wii.com/iwata_asks/mario25th/vol2_page3.jsp

Quote
Uemura
But that wasn't on purpose. We just couldn't make enough. What's more, problems were appearing one after the other. One example was the "disappearing ball"...

Iwata
That was a bug which caused the ball or white lines in  Baseball to disappear under certain circumstances.

Uemura
We had stretched to make it, so the thermal design was insufficient and it would heat up fast, causing the sprite for quickly displaying the graphics to disappear. Another problem was the  square buttons on the controller. They would get stuck down.

Salduchi

I'm going to test out baseball on mine and see how it goes. I'll update back later. I actually enjoy that game lol.

If Fantasy Zone starts glitching after x amount of time, perhaps its caused by a memory leak.

P

Famicom only has 2 kB RAM and you program everything in assembly (except for a few KOEI games that seems to have been made using a C-like scripting language) and you have full manual control of memory. I don't think you'd normally do much memory allocation. Memory leakage is probably an uncommon problem on old systems like this.

I think it's an overheating problem, they mentioned something about that in the Iwata Asks.

Salduchi

I played 3 games of baseball last night, about 2 hours of gameplay. No issues worth mentioning.

krzy

OAM memory (which holds sprites data inside PPU) is made of dynamic memory, which needs constant refreshing (reloading). Nesdev wiki says that reloading them frame after  frame (which every game does) is enough for the data not to be corrupted..
So probably the first PPU releases when get hot was not able to keep the data between frames and that's why ball in the game, described in article,  disappeared.