MiSTer FPGA Forum

I am seeing graphical glitches in the Japanese version of Alien Soldier when played with the US and JP regions of the Genesis core. I have double-checked my ROM from two different sources (one of them being HTGDB). Strangely, this anomaly disappears when the rom runs on the EU version of the core. I made sure to run update_all.sh successfully before capturing these images.

Is someone else able to reproduce this?

(alternate link for video: https://photos.app.goo.gl/ZdsTMz8W8gU1EDW8A)

I only had that issue when I wasn't using SD RAM module. If you use the onboard mister RAM this can happen. Make sure that core is set to use the external SD RAM.

Thanks for the tip! I messed around with the Miscellaneous -> ROM Storage option, and it did affect the lines, but didn't solve the issue. However, setting CPU Turbo to HIGH completely fixed the issue for me. I wonder what's up with that!

Either way, I'm satisfied with this fix for the time being.

Turns out, maybe my ROM was the issue. I tried another JP ROM sent to me and it works fine.

Do you have the MD5 off of each ROM (the working and non-working)? Do the glitches occur on original hardware? (JP MegaDrive)

aberu wrote: ↑Thu Dec 23, 2021 2:24 pm Do you have the MD5 off of each ROM (the working and non-working)? Do the glitches occur on original hardware? (JP MegaDrive)

I have a JP cart of this and it does not happen on a real megadrive. I've had this exact same glitch happen when using the mister onboard DDR3, but using the SDRAM solved it. Unsure what caused it in this situation, I guess it was a bad ROM.

DDR3 will behave abnormally. SDRAM is more accurate, but the core isn't 100% perfect (I don't think any core is) in a measurable sense. Usually perceptible with SDRAM it's hard to notice any problems with the Genesis core though.

I have two roms of this game, one for EU region and one for JP. In both cases game by default starts in EU mode.
EU rom can be started in only EU mode and has correct speed with EU setting and is too fast in JP or US when switched to it.
JP rom can be started in EU and JP modes and has correct speed in JP mode and is too slow in EU mode. Works the same as JP mode when switched to it after initial region lockout check.

Now the issue with flashing artifacts during weapon select screen happen only when game is started in EU mode and then switched to JP/US. It happen in both roms in exactly the same way. The way to play this game glitch free in 60Hz is to start Japanese rom in JP and... best not change it : ) BTW. Triggering reset after first starting game in EU and then changing mode to JP doesn't make this issue go away. Rom need to be reloaded in 60Hz mode. When game is loaded it in the US mode and reset after changing to JP game runs fine.

I checked in emulator if the same behavior can be observed and in Fusion 3.64 it works the same way except two things
1) artifacts have different colors!
2) after soft reset in emulator game does not have glitch - this one is easily explained by emulator clearing out memory

Imho the only way to be sure what is the correct behavior in order to be able to consider this a bug of sorts would be if someone with modded Genesis/Megadrive with the game (or flashcard) tested if game exhibits the same behavior with mode switching as Mister and what are its colors. Also if real reset should make bug go away without having to power cycle console.

BTW. ROM storage option doesn't change anything regarding this glitch, nor does any other option I have tried except setting CPU speed to Turbo.

i might think you are playing japan version because it is 60 fps NTCS version
you can try to use those IPS patches to convert all your europe region roms to NTSC. works great for me with no issues.
all my europe roms starts default as US region.

https://www.romhacking.net/hacks/4596/