How to check what's causing graphics glitches on AR 4M Plus?

[garou64]

Sorry I could not word the thread title better because of the character limit.

I have a Model 1 PAL Saturn. I also have an Action Replay 4M Plus in it. I had issues before with graphics glitching in games that require the 1M or 4M RAM expansion. (both SNK and Capcom games). I installed a Phantom modchip in my console last year, and after installing it I did not experience these glitches up until recently, when I had to take apart my Saturn to install a Fenrir ODE in it. 

I read recently that some Action Replay carts have this issue where they don't properly switch between the 1M and the 4M RAM when booting certain games, and that could be causing these glitches to appear. But I read that this could also be caused by the cartridge slot in the console not "reading" the cart correctly. Now I should say that I never had the issue of the cart not being recognized by the console itself. The Action Replay menu always loads when I boot the console.

I'd like to know how to determine exactly what is causing the glitches: is it the cart or is it the cartridge slot? I tested the AR cart in another console (same Model 1 as mine), and the glitches occured there too. But maybe this other console has a bad cartridge slot too. So that's what I'm asking , if there is a way to tell the cause of the issue before I go and spend money on another console or another cart.

Also, would one of those red Pseudo Saturn carts with the physical switch on it help with this problem of games using the correct 1M or 4M RAM?

Thanks.

[zyrobs]

The AR cart does not switch between 1M and 4M modes. It's just 4M, which is meant to be backwards compatible with 1M.

However, three SNK games (Samurai Showdown, Fatal Fury and one other I forgot) were programmed wrong and access a memory address which is blank data on the 4M cart. Therefore they only work with 1M carts, and will glitch out on any 4M cart (except for ones that have a physical switch to toggle between 1M/4M modes).

I don't know how the Pseudo Saturn carts work, they are largely useless if you have a modchip or an ODE.

[garou64]

Jan 2, 2021 19:22:33 GMT zyrobs said:

The AR cart does not switch between 1M and 4M modes. It's just 4M, which is meant to be backwards compatible with 1M.

However, three SNK games (Samurai Showdown, Fatal Fury and one other I forgot) were programmed wrong and access a memory address which is blank data on the 4M cart. Therefore they only work with 1M carts, and will glitch out on any 4M cart (except for ones that have a physical switch to toggle between 1M/4M modes).

I don't know how the Pseudo Saturn carts work, they are largely useless if you have a modchip or an ODE.

So if other games apart from those 3 SNK ones exhibit these graphical glitches is it safe to assume that the cartridge slot is the culprit ?

[zyrobs]

Either the cartridge or the connector.
If the glitches are the exact same between two consoles, then it's either the cart being bad or the cart pins having contact errors. The AR carts are held together with normal phillips (plus head) screws, so it would be trivial to take them apart and clean the pins. Since the pins are very thin on the Saturn, it's very common for the accumulated gunk on the pins to cause contact errors.