We present another round of fixes and improvements, a particularly happy one because it closes two long standing issues in two important cores.
OutRun
Since April 2023, OUTRUN exhibited persistent PCM sound playback issues in which certain PCM instruments (mainly percussion) were triggered when they should not have been, were not properly cut off, or were missed entirely. After several patches, the situation was not completely solved. Finally, the puzzle was solved this week, and we can confidently close this issue.
CPS2
Raster effects refer to the game modifying the video configuration while the screen is being displayed. This is usually done with a line counter that interrupts the CPU at the time the effect must happen. These effects are difficult to debug because you cannot isolate the video circuitry from the CPU so exploring the problem is very time consuming. The computer simulations to analyze the problem took well over one day, so we could not advance quickly with this. In the end, there were two bugs behind this problem. These are fixed and the CPS2 core finally has clean raster effects under all conditions.
Ghosts'n Goblins
The top horizontal line was missing for sprites in GnG and a couple of other CAPCOM games. Not particularly easy to notice as sprites usually move around the centre of the screen. Once the problem was identified it was easy to fix it.
Low Volume
We try to keep volume across cores more or less similar. The Rolling Thunder core was relatively low so we have boosted it +3dB without producing clipping. It is still a bit lower than other cores, though. Remember you can control the volume with F4/F5 keys on your keyboard for all JT cores. A similar problem happened for Kageki and it has been improved too.
Screen orientation
Here is a tricky one. TheJesusFish reported that some games were rotated incorrectly compared to the default orientation seen in MAME. After reviewing them, I agreed that most of the reported cases should be flipped. If you are using a HDMI screen or the Analog Pocket, this won't affect you. But if you are on an analog screen, you may need to adjust the core flip setting after this change. The games affected are 1942, 1943, Vulgus, Exed Exes, GunSmoke, Karate Champ and Rumba Lumba.
X-Men Screen Ratio
When we removed the black bars around X-Men we did not update the expected aspect ratio in the MiSTer core definition. So the old value that compensated for the black bars was still used, and it made things look wider. This has been corrected now.
TMNT2 Alternatives Folder
The MRA files for TMNT2 alternative versions are now located in the Turtles in Time folder.
Nekketsu Koha Kunio-Kun Not Booting-up
When I made our own 6502 CPU module a few weeks ago, the Japanese version of Renegade stopped working. The reason was that the new CPU could output intermediate address values under some circumstances. The address decoding logic would react to some of these spurious values. I modified the CPU to indicate when the address is valid and we got Kunio-Kun back into action!
This is all for this week. We are still working on the NGPC game saving feature, which is taking a lot of our time. Another conondrum is how to solve the memory requirements for CPS3. I am even considering whether a special memory module would help in this case. It is still early to tell. Please bear with me.