再現方法:
This game is a long visual scene, like an anime.
Once in a while (not often), the screen flashes in the same way that Doraemon does (seems to be scroll register on VDC).
Once in a while (not often), the screen flashes in the same way that Doraemon does (seems to be scroll register on VDC).
The flicker will certainly happen, but the frequency is very low (maybe 1 time every 10 seconds, and only in some parts of the story).
I tried playing this on a real machine.
I did not see any video issues like in your capture between 8:30 and 9:30 (while the main character is talking on the telephone).
However, I did see something similar to the video issues like in your capture between 15:10 and 16:00, when text is printed. *BUT*, on a real machine, the problem is smaller, and it only affects the lower half of the screen (the text area, not the picture area).
Additionally, I saw some other video "noise" sometimes on the real machine. This "noise" was limited to one scanline, where a few pixels of color went in a place that should be dark.
...In the 1980's, this kind of "noise" was caused by writing to the video memory/palette registers/video controller exactly as the raster scan happened for that line; it was better to schedule these writes either during the VBLANK, or at least when the raster was at a different point on the screen (for example, draw the top half of the screen when you know it has already been rasterized; when the raster is drawing the bottom half).
SEEK TIME 実装で改善しませんでした.
前回までの様子を見ますと、CD から ADPCM RAM の読み込みが終わったときに scroll register を更新しているタイミングが可視領域になっているものと思われます.
重要度が低いのと改善が難しそうなので保留にいたします.
20190706.pac still has this issue, but I have new information.
If playing from the start, the screen will flash in the bedroom scene (like MVI_0125.MP4_snapshot_08.36_[2018.12.08_18.10.55].jpg above) about once every 5 seconds.
But if you stop the game, then start the game again, and select this scene (02) as the starting point, the flashing does not occur in this scene.